Megan Ryan

Differential growth response of Rytidosperma species (wallaby grass) to phosphorus application and its implications for grassland management

Publisher: Wiley

Date: 29-04-2015

DOI: 10.1111/GFS.12170

Root diameter decreases and rhizosheath carboxylates and acid phosphatases increase in chickpea during plant development

Publisher: Springer Science and Business Media LLC

Date: 29-06-2022

DOI: 10.1007/S11104-022-05579-Y

Abstract: This study investigated whether root traits at the seedling stage are maintained at the flowering stage in two chickpea ( Cicer arietinum ) genotypes with contrasting root morphology and physiology and whether the genotype with greater rhizosheath carboxylates mobilises more poorly-available phosphorus (P) pools to increase shoot P at flowering odding and seed yield at maturity. Two chickpea genotypes were grown in a low P soil with or without P addition (0 and 40 µg P g −1 soil as KH 2 PO 4 ) under controlled glasshouse conditions and harvested at seedling, flowering odding, physiological maturity. At the seedling and flowering odding stages, ICC2884 had thinner roots and greater root mass ratio, specific root length and rhizosheath carboxylates per root dry weight (DW) than ICC456. Both genotypes had smaller root diameter, higher carboxylates and acid phosphatase activity in rhizosheath soil at flowering odding than at seedling. In the rhizosheath soil of both genotypes, NaHCO 3 -Pi concentration was depleted under P0 only under both P0 and P40, NaHCO 3 -Po concentration increased while NaOH-Pi and NaOH-Po concentrations decreased at the seedling stage but accumulated at the flowering odding stage, relative to the bulk soil. ICC2884 did not mobilise more poorly available soil P or acquire more P at the seedling or flowering odding stages, or produce higher seed yields than ICC456. ICC2884 and ICC456 maintained the difference in root morphological and physiological characteristics from the seedling stage to the flowering odding stage. The genotype with greater rhizosheath carboxylates (root DW basis) did not produce higher yield than genotype with less rhizosheath carboxylates.

An agronomic study of legacy effects from annual legume pastures in acid soils

Publisher: Wiley

Date: 10-04-2023

DOI: 10.1111/JAC.12642

Abstract: The use of acid soil‐tolerant annual legume pasture species and liming to raise soil pH can have legacy effects that improve subsequent wheat crop growth in acid soils. We established a two‐year experiment in a semi‐arid environment with and without historical lime application to investigate how acid soils (±lime) influence the legacy effects of annual legume pastures. We measured legume and cereal growth and yield, soil‐borne disease incidence, rhizosheath organic acid type and amount, legume biological nitrogen fixation (BNF) and soil moisture in Year 1, and soil microbial biomass carbon (MBC) and wheat yield and quality in Year 2. Minor differences in soil moisture and soil‐borne diseases occurred between cereals and legumes, and the poor BNF contribution of all pasture legumes improved in lime treatments. Pasture legumes produced more organic acids than cereals, which increased in limed treatments. Soil MBC in Year 2 was greater following legumes than cereals. Year 2 wheat grain yield increased following pasture legumes, more so in limed treatments. The contribution of organic acid exudation by annual legume pastures to microbial community legacy effects warrants further scrutiny in semi‐arid environments, particularly when acid soils limit typical rotational benefits.

Rhizosphere carboxylates and morphological root traits in pasture legumes and grasses

Publisher: Springer Science and Business Media LLC

Date: 10-12-2015

DOI: 10.1007/S11104-015-2770-4

Zinc bioavailability in wheat grain in relation to phosphorus fertiliser, crop sequence and mycorrhizal fungi

Publisher: Wiley

Date: 25-03-2008

DOI: 10.1002/JSFA.3200

Water relations and adaptations to increasing water deficit in three perennial legumes, Medicago sativa, Dorycnium hirsutum and Dorycnium rectum

Publisher: Springer Science and Business Media LLC

Date: 16-12-2006

DOI: 10.1007/S11104-006-9155-7

Variation in morphological and physiological parameters in herbaceous perennial legumes in response to phosphorus supply

Publisher: Springer Science and Business Media LLC

Date: 19-12-2010

DOI: 10.1007/S11104-009-0249-X

Opportunistic Mediterranean agriculture – Using ephemeral pasture legumes to utilize summer rainfall

Publisher: Elsevier BV

Date: 09-2013

DOI: 10.1016/J.AGSY.2013.06.001

Salinity tolerance and avoidance mechanisms at germination among messina (

Publisher: CSIRO Publishing

Date: 21-06-2021

DOI: 10.1071/CP20427

Abstract: Messina (Melilotus siculus) cv. Neptune, an annual pasture legume native to the Mediterranean Basin, has recently been released for saltland pastures in southern Australia following demonstration of biomass production and persistence superior to other commercial pasture legumes in saline environments prone to winter waterlogging. Self-regenerating annual pasture legumes also require seed adaptations for both tolerating and avoiding salinity at germination in these environments. This study examined ersity within Neptune and 20 other messina accessions for salt tolerance at germination, recovery of germinability from temporary salt stress, and timing and extent of hardseed softening, compared with balansa clover (Trifolium michelianum) cv. Frontier, burr medic (Medicago polymorpha) cv. Scimitar and white melilot (Melilotus albus) cv. Jota. Germination rates after 14 days at 300 mM NaCl relative to 0 mM NaCl were ≥99% for Neptune and 18 other messina accessions, 66% for Scimitar, 21% for Jota and 11% for Frontier. No genotype germinated at 600 mM NaCl however, when transferred to 0 mM NaCl after 14 days at 600 mM, all genotypes except Scimitar and Jota recovered partial germination, ranging from 13% to 93% of controls (0 mM NaCl for 28 days). The softening rate of hard (impermeable) seeds in the field varied among genotypes, with deferral of hardseed softening until late autumn–early winter, when rainfall is more likely, indicating greater persistence. The months in which the hardseed level first became significantly lower than the initial level (in freshly harvested seeds) after placement on the soil surface in December were: March for Frontier April for Scimitar, Jota and Neptune and March–July for all messina accessions. This study confirmed that messina has high salt tolerance and several avoidance mechanisms at germination that contribute to its adaptation to saline soils in southern Australia. Several messina accessions were superior to Neptune for in idual traits which could be exploited for plant breeding. These results also have implications for saltland pastures in other regions of the world with Mediterranean-type climates.

Harvesting subterranean clover seed – current practices, technology and issues

Publisher: CSIRO Publishing

Date: 26-03-2021

DOI: 10.1071/CP20269

Abstract: Subterranean clover (Trifolium subterraneum L.) is Australia’s most widely sown annual pasture legume. Its widespread use as a pasture plant requires a well-functioning seed production industry, and Australia is the only significant producer of subterranean clover seed globally. However, the sustainability of this industry is under threat due to its reliance on ageing harvest equipment and the resultant environmental impacts. In order to evaluate seed harvesting practices, technology, and issues, we report on case studies, workshops, and a survey of seed producers across southern Australia. The Horwood Bagshaw Clover Harvester, designed in the 1950s, remains the most popular subterranean clover seed harvester. We discuss its use and modifications, and document several contemporary issues facing the seed production industry. Issues are primarily soil erosion and degradation the expensive, slow and labour-intensive harvest process and poor reliability and maintainability of harvesters that are now at least 30 years old. We conclude the root cause of these issues is the suction harvest technology utilised by the Horwood Bagshaw Clover Harvester. Analysis of the current harvest system is provided to support the development of new approaches to harvest subterranean clover seeds.

Relative amounts of soluble and insoluble forms of phosphorus and other elements in intraradical hyphae and arbuscules of arbuscular mycorrhizas

Publisher: CSIRO Publishing

Date: 2007

DOI: 10.1071/FP06242

Abstract: Transport of phosphorus (P) into host plants and its release to root cells is an important function of arbuscular mycorrhizal fungi (AMF). However, relatively little is known about the forms and water solubilities of P compounds in specific locations in the intraradical fungal structures. We determined concentrations and solubility of P components in these structures in white clover (Trifolium repens L.). Plants were grown in the field (colonised by indigenous AMF) or in the glasshouse (inoculated with Glomus intraradices). Mycorrhizas were cryo-fixed in liquid nitrogen immediately (control) or after treatments designed to destroy cell membranes and extract solubles. Thirty to 70% of total P in hyphae and 100% in arbuscules was not extracted. The unextracted proportion of P was higher in the inoculated plants suggesting an environmental effect. It is proposed that the large component of non-extractable P in the arbuscules is involved in the tight regulation of inorganic P release to the host cells. In control roots magnesium, potassium and P were present in hyphae in molar ratios 1 : 2 : 4, further evidence that this relationship may be universal for AMF, and that other P-balancing cations are present but undetectable by the analytical technique.

Little evidence that farmers should consider abundance or diversity of arbuscular mycorrhizal fungi when managing crops

Publisher: Wiley

Date: 10-07-2018

DOI: 10.1111/NPH.15308

Abstract: Contents Summary 1092 I. Introduction 1093 II. Investigating activity of AMF in agroecosystems 1093 III. Crop benefit from AMF: agronomic and mycorrhizal literature differ 1094 IV. Flawed methodology leads to benefits of mycorrhizas being overstated 1094 V. Rigorous methodology suggests low colonisation by AMF can sometimes reduce crop yield 1095 VI. Predicting when mycorrhizas matter for crop yield 1096 VII. Crop genotype 1099 VIII. Fungal genotype 1100 IX. Complex interactions between the mycorrhizal fungal and soil microbial communities 1102 X. Phosphorus-efficient agroecosystems 1102 XI. Conclusions 1103 Acknowledgements 1104 References 1104 SUMMARY: Arbuscular mycorrhizal fungi (AMF) are ubiquitous in agroecosystems and often stated to be critical for crop yield and agroecosystem sustainability. However, should farmers modify management to enhance the abundance and ersity of AMF? We address this question with a focus on field experiments that manipulated colonisation by indigenous AMF and report crop yield, or investigated community structure and ersity of AMF. We find that the literature presents an overly optimistic view of the importance of AMF in crop yield due, in part, to flawed methodology in field experiments. A small body of rigorous research only sometimes reports a positive impact of high colonisation on crop yield, even under phosphorus limitation. We suggest that studies vary due to the interaction of environment and genotype (crop and mycorrhizal fungal). We also find that the literature can be overly pessimistic about the impact of some common agricultural practices on mycorrhizal fungal communities and that interactions between AMF and soil microbes are complex and poorly understood. We provide a template for future field experiments and a list of research priorities, including phosphorus-efficient agroecosystems. However, we conclude that management of AMF by farmers will not be warranted until benefits are demonstrated at the field scale under prescribed agronomic management.

Strategies and agronomic interventions to improve the phosphorus-use efficiency of temperate farming systems

Publisher: Springer Science and Business Media LLC

Date: 08-07-2011

DOI: 10.1007/S11104-011-0880-1

A mycorrhizal revolution

Publisher: Elsevier BV

Date: 08-2018

DOI: 10.1016/J.PBI.2017.12.004

Abstract: It has long been postulated that symbiotic fungi facilitated plant migrations onto land through enhancing the scavenging of mineral nutrients and exchanging these for photosynthetically fixed organic carbon. Today, land plant-fungal symbioses are both widespread and erse. Recent discoveries show that a variety of potential fungal associates were likely available to the earliest land plants, and that these early partnerships were probably affected by changing atmospheric CO

Multiple adaptive responses of Australian native perennial legumes with pasture potential to grow in phosphorus- and moisture-limited environments

Publisher: Oxford University Press (OUP)

Date: 05-2010

DOI: 10.1093/AOB/MCQ040

Implications of co-contamination with aged heavy metals and total petroleum hydrocarbons on natural attenuation and ecotoxicity in Australian soils

Publisher: Elsevier BV

Date: 12-2018

DOI: 10.1016/J.ENVPOL.2018.08.040

Abstract: The bioremediation of historic industrial contaminated sites is a complex process. Co-contamination, often with lead which was commonly added to gasoline until 16 years ago is one of the biggest challenges affecting the clean-up of these sites. In this study, the effect of heavy metals, as co-contaminant, together with total petroleum hydrocarbons (TPH) is reported, in terms of remaining soil toxicity and the structure of the microbial communities. Contaminated soil s les from a relatively hot and dry climate in Western Australia were collected (n = 27). Analysis of soils showed the presence of both contaminants, TPHs and heavy metals. The Microtox test confirmed that their co-presence elevated the remaining ecotoxicity. Toxicity was correlated with the presence of lead, zinc and TPH (0.893, 0.599 and 0.488), respectively, assessed using Pearson Correlation coefficient factor. Next Generation Sequencing of soil bacterial 16S rRNA, revealed a lack of dominate genera however, despite the variation in soil type, a few genera including Azospirillum spp. and Conexibacter were present in most soil s les (85% and 82% of all soils, respectively). Likewise, many genera of hydrocarbon-degrading bacteria were identified in all soil s les. Streptomyces spp. was presented in 93% of the s les with abundance between 7% and 40%. In contrast, Acinetobacter spp. was found in only one s le but was a dominant member of (45%) of the microbial community. In addition, some bacterial genera were correlated to the presence of the heavy metals, such as Geodermatophilus spp., Rhodovibrio spp. and Rubrobacter spp. which were correlated with copper, lead and zinc, respectively. This study concludes that TPH and heavy metal co-contamination significantly elevated the associated toxicity. This is an important consideration when carrying out risk assessment associated with natural attenuation. This study also improves knowledge about the dynamics of microbial communities in mixed contamination scenarios.

Phosphorus uptake and toxicity is delimited by mycorrhizal symbiosis in P-sensitive Eucalyptus marginata but not in P-tolerant Acacia celastrifolia

Publisher: Cold Spring Harbor Laboratory

Date: 28-09-2021

DOI: 10.1101/2021.09.28.462111

Abstract: Many plant species from regions with ancient, highly-weathered nutrient-depleted soils have specialised adaptations for acquiring P and are sensitive to excess P-supply. Mycorrhizal associations may regulate P-uptake at high external P-concentrations, potentially reducing P-toxicity. We predicted that excess P-application will negatively impact species from the nutrient-depleted jarrah forest of Western Australia and that mycorrhizal inoculation will reduce P-toxicity by regulating P-uptake. For seedlings of the N 2 -fixing legume Acacia celastrifolia and the tree species Eucalyptus marginata , we measured growth at P-concentrations of 0 to 90 mg kg −1 soil and in relation to inoculation with the arbuscular mycorrhizal fungus (AMF) Rhizophagus irregularis . Non-inoculated A . celastrifolia maintained leaf P-concentrations at mg g −1 dry mass (DM) across the range of external P-concentrations. However, for non-inoculated E . marginata , as external P-concentrations increased leaf P also increased, reaching mg g −1 DM at 30 mg P kg −1 soil. A . celastrifolia DM increased with increasing external P-concentrations, while E . marginata DM was maximal at 15 mg P kg −1 soil, declining at higher external P concentrations. Neither DM nor leaf P of A . celastrifolia were affected by inoculation with AMF. For E . marginata , even at 90 mg P kg −1 soil, inoculation with AMF resulted in leaf P remaining mg g −1 DM, and DM being maintained. These data strengthen the evidence base that AMF may not only facilitate P-uptake at low external P-concentrations, but are also important for moderating P-uptake at elevated external P-concentrations and maintaining plant P concentrations within a relatively narrow concentration range.

Phosphorus-utilisation efficiency and leaf-morphology traits of Rytidosperma species (wallaby grasses) that differ in their growth response to phosphorus fertilisation

Publisher: CSIRO Publishing

Date: 2016

DOI: 10.1071/BT15202

Abstract: Rytidosperma species are perennial grasses found in cool temperate grasslands of Australia. The species differ in their intrinsic growth rates, response to phosphorus (P) fertiliser application and critical external P requirements (P required for 90% maximum growth). The present study examined whether internal P-utilisation efficiency (PUE) by Rytidosperma species influenced these differences. The PUE of nine Rytidosperma species and two grasses of Mediterranean origin, Bromus hordeaceus L. and Lolium perenne L., was assessed using alternative measures of shoot P concentration or its reciprocal. No measure of PUE was correlated with the critical external P requirements of the species. One measure of PUE, shoot dry matter per unit P, when assessed at a common shoot P content was correlated with potential growth rate (P 0.001 r = 0.93 4 mg shoot P). However, other measures of PUE were not correlated with potential growth rates. All of the fast-growing species (B. hordeaceus, L. perenne, Rytidosperma duttonianum (Cashmore) Connor & Edgar and Rytidosperma richardsonii (Cashmore) Connor & Edgar) exhibited high PUE, whereas PUE varied substantially among the slower-growing species. The fast-growing Rytidosperma species differed in the contribution that area-based P concentration of leaves and specific leaf area (SLA) made to the achievement of high PUE, and they retained shoot-morphology traits normally associated with slow-growing species such as smaller leaf area, smaller SLA and higher leaf dry matter content.

Plants in constrained canopy micro-swards compensate for decreased root biomass and soil exploration with increased amounts of rhizosphere carboxylates

Publisher: CSIRO Publishing

Date: 2017

DOI: 10.1071/FP16398

Abstract: Root traits related to phosphorus (P) acquisition are used to make inferences about a species’ P-foraging ability under glasshouse conditions. However, the effect on such root traits of constrained canopy spread, as occurs in dense pasture swards, is unknown. We grew micro-swards of Trifolium subterraneum L. and Ornithopus compressus L. at 15 and 60 mg kg–1 soil P in a glasshouse. Shoots either spread beyond the pot perimeter or were constrained by a cylindrical sleeve adjusted to canopy height. After 8 weeks, shoot and root dry mass (DM), shoot tissue P concentration, rhizosphere carboxylates, arbuscular mycorrhizal (AM) fungal colonisation, total and specific root length (TRL and SRL respectively), average root diameter (ARD) and average root hair length (ARHL) were measured. In all species and treatments, constrained canopy spread decreased root DM (39–59%), TRL (27–45%) and shoot DM (10–28%), and increased SRL (20–33%), but did not affect ARD, ARHL and AM fungal colonisation. However, shoot P concentration and content increased, and rhizosphere carboxylates increased 3.5 to 12-fold per unit RL and 2.0- to 6.5-fold per micro-sward. Greater amounts of rhizosphere carboxylates when canopy spread was constrained appeared to compensate for reduced root growth enabling shoot P content to be maintained.

Root morphological traits that determine phosphorus-acquisition efficiency and critical external phosphorus requirement in pasture species

Publisher: CSIRO Publishing

Date: 2016

DOI: 10.1071/FP16037

Abstract: Annual pasture legume species can vary more than 3-fold in their critical external phosphorus (P) requirement (i.e. P required for 90% of maximum yield). In this work we investigated the link between root morphology, P acquisition and critical external P requirement among pasture species. The root morphology acclimation of five annual pasture legumes and one grass species to low soil P availability was assessed in a controlled-environment study. The critical external P requirement of the species was low (Dactylis glomerata L., Ornithopus compressus L., Ornithopus sativus Brot.), intermediate (Biserrula pelecinus L., Trifolium hirtum All.) or high (Trifolium subterraneum L.). Root hair cylinder volumes (a function of root length, root hair length and average root diameter) were estimated in order to assess soil exploration and its impact on P uptake. Most species increased soil exploration in response to rates of P supply near or below their critical external P requirement. The legumes differed in how they achieved their maximum root hair cylinder volume. The main variables were high root length density, long root hairs and/or high specific root length. However, total P uptake per unit surface area of the root hair cylinder was similar for all species at rates of P supply below critical P. Species that maximised soil exploration by root morphology acclimation were able to prolong access to P in moderately P-deficient soil. However, among the species studied, it was those with an intrinsic capacity for a high root-hair-cylinder surface area (i.e. long roots and long root hairs) that achieved the lowest critical P requirement.

Belowground solutions to global challenges: special issue from the 9th symposium of the International Society of Root Research

Publisher: Springer Science and Business Media LLC

Date: 11-02-2017

DOI: 10.1007/S11104-017-3200-6

Contrasting patterns in biomass allocation, root morphology and mycorrhizal symbiosis for phosphorus acquisition among 20 chickpea genotypes with different amounts of rhizosheath carboxylates

Publisher: Wiley

Date: 29-04-2020

DOI: 10.1111/1365-2435.13562

Improving the performance of canola in retained wheat stubble

Publisher: CSIRO Publishing

Date: 2016

DOI: 10.1071/AR05394

Abstract: Four field experiments investigated strategies to reduce the negative effects of surface-retained wheat stubble on the emergence, growth, and yield of canola. All experiments compared 3 stubble treatments: (1) no stubble (stubble removed or burnt) (2) stubble-spread (6 t/ha wheat stubble evenly distributed on the surface) and (3) stubble-inter-row (6 t/ha stubble distributed on the inter-rows only). Seedling emergence was reduced in the presence of evenly spread stubble compared with no stubble, and the emerged seedlings had longer hypocotyls, reduced leaf number, and reduced biomass. Reduced shoot growth was not associated with lower shoot N concentration. These early effects on shoot growth persisted at 3 of the 4 sites, resulting in average yield reductions of 26% (range 0–59%) in the stubble-spread treatments compared with no stubble. Restricting stubble to the inter-rows resulted in an initial reduction in seedling growth compared with no stubble, but this difference had diminished by flowering. The yield for the stubble inter-row treatment was similar to no stubble at 2 sites and intermediate between no stubble and stubble-spread at the other 2 sites, with an overall yield reduction of 5.3% compared with no stubble. The results indicate that the negative effects on canola performance of surface-retained wheat stubble can be largely eliminated by adopting sowing techniques that push wheat stubble away from the seeding row and onto the inter-row. This provides a viable option to stubble burning and maintains the benefits of stubble retention.

Citrate and malonate increase microbial activity and alter microbial community composition in uncontaminated and diesel-contaminated soil microcosms

Publisher: Copernicus GmbH

Date: 21-09-2016

DOI: 10.5194/SOIL-2-487-2016

Abstract: Abstract. Petroleum hydrocarbons (PHCs) are among the most prevalent sources of environmental contamination. It has been hypothesized that plant root exudation of low molecular weight organic acid anions (carboxylates) may aid degradation of PHCs by stimulating heterotrophic microbial activity. To test their potential implication for bioremediation, we applied two commonly exuded carboxylates (citrate and malonate) to uncontaminated and diesel-contaminated microcosms (10 000 mg kg−1 aged 40 days) and determined their impact on the microbial community and PHC degradation. Every 48 h for 18 days, soil received 5 µmol g−1 of (i) citrate, (ii) malonate, (iii) citrate + malonate or (iv) water. Microbial activity was measured daily as the flux of CO2. After 18 days, changes in the microbial community were assessed by a community-level physiological profile (CLPP) and 16S rRNA bacterial community profiles determined by denaturing gradient gel electrophoresis (DGGE). Saturated PHCs remaining in the soil were assessed by gas chromatography–mass spectrometry (GC-MS). Cumulative soil respiration increased 4- to 6-fold with the addition of carboxylates, while diesel contamination resulted in a small, but similar, increase across all carboxylate treatments. The addition of carboxylates resulted in distinct changes to the microbial community in both contaminated and uncontaminated soils but only a small increase in the biodegradation of saturated PHCs as measured by the n-C17 : pristane biomarker. We conclude that while the addition of citrate and malonate had little direct effect on the biodegradation of saturated hydrocarbons present in diesel, their effect on the microbial community leads us to suggest further studies using a variety of soils and organic acids, and linked to in situ studies of plants, to investigate the role of carboxylates in microbial community dynamics.

Growth suppression of canola through wheat stubble II. Investigating impacts of hypocotyl elongation using simulated stubble

Publisher: Springer Science and Business Media LLC

Date: 03-2006

DOI: 10.1007/S11104-005-4643-8

The first genetic maps for subterranean clover (Trifolium subterraneum L.) and comparative genomics with T. pratense L. and Medicago truncatula Gaertn. to identify new molecular markers for breeding

Publisher: Springer Science and Business Media LLC

Date: 05-08-2011

DOI: 10.1007/S11032-011-9612-8

Petiole length reduction is an indicator of waterlogging stress for Trifolium subterraneum ssp. yanninicum

Publisher: Springer Science and Business Media LLC

Date: 13-04-2022

DOI: 10.1007/S11104-022-05404-6

Abstract: The pasture legume Trifolium subterraneum ssp. yanninicum exhibits waterlogging tolerance. This study investigates ersity for waterlogging tolerance within ssp. yanninicum . We tested the hypotheses that (1) variation for waterlogging tolerance exists within ssp. yanninicum and (2) is related to phenotypic and growth trait differences, which (3) reflect eco-geographic variables at site of origin. Twenty-eight erse ssp. yanninicum ecotypes collected from the Mediterranean region and four cultivars were grown in a controlled environment glasshouse. Seedling traits were measured at 14 and 21 days after sowing. Waterlogged and free-draining (control) treatments were then imposed for 28 days. Relative distance and multivariate plasticity indices were calculated. Under waterlogging, shoot (87–108% of controls) and root (80–116% of controls) relative growth rates (RGRs) differed significantly among ssp. yanninicum . Waterlogging tolerance, as assessed by shoot RGR, had strong positive correlations with root RGR ( r = 0.86 P 0.001), petiole length ( r = 0.59 P 0.001) and leaf size ( r = 0.55 P 0.01) under waterlogging. The proportion of biomass as leaf increased under waterlogging, due to leaf size being maintained (mean 102% of controls), but petiole length decreased (mean 84% of controls). Petiole length was the most plastic trait. Seed size, seedling traits, maturity duration and eco-geographic variables at site of origin were not related to waterlogging tolerance. Wide variation in waterlogging tolerance exists within ssp. yanninicum . Petiole length reduction, an easy-to-measure and non-destructive indicator, could be used as a preliminary selection tool when screening large numbers of ssp. yanninicum for waterlogging tolerance in a breeding program.

Growth, yield and seed composition of native Australian legumes with potential as grain crops

Publisher: Wiley

Date: 14-11-2012

DOI: 10.1002/JSFA.4706

Abstract: Many Australian native legumes grow in arid and nutrient-poor environments. Yet few Australian herbaceous legumes have been investigated for domestication potential. This study compared growth and reproductive traits, grain yield and seed composition of 17 native Australian legumes with three commercial grain legumes. Seed yields of seven native legumes were > 40% of Cicer arietnum, with highest seed yields and harvest indices in Glycine sp. (14.4 g per plant, 0.54 g g(-1) ) and Lotus cruentus (10.2 g per plant, 0.65 g g(-1) ). Five native species flowered earlier than field pea (Pisum sativa) (109 days), though many were slower to flower and set seed. Largest seeds were found in Glycine canescens (17 mg), with seed of other native species 14 times smaller than commercial cultivars. Seed composition of many native legumes was similar to commercial cultivars (200-330 g protein kg(-1) dry weight (DW), 130-430 g dietary fibre kg(-1) DW). Two Cullen species had high fat content (>110 g kg(-1) DW) and Trigonella sauvissima had the highest crude protein content (370 g kg(-1) DW). The seed composition and reproductive traits of some wild native Australian legumes suggest they could offer potential as grain crops for soils and environments where the current grain legumes are uneconomic. Further evaluation of genetic ersity, especially for seed size, overall productivity, and reproductive development is needed.

Seasonal and diurnal variation in the stomatal conductance and paraheliotropism of tedera (Bituminaria bituminosa var. albomarginata) in the field

Publisher: CSIRO Publishing

Date: 2013

DOI: 10.1071/FP12228

Abstract: The mechanisms of drought resistance in perennial legumes are poorly understood. We explored the diurnal and seasonal variation (May, August, February) in stomatal conductance (gs) and paraheliotropism of three tedera accessions (Bituminaria bituminosa (L.) C.H. Stirton var. albomarginata) and lucerne (Medicago sativa L.), both perennial legumes, grown in the field. For the tedera accessions, there was a significant reduction in gs during the day in May (late autumn) and February (summer), but there was little reduction for lucerne. The peak leaf angle in the tedera accessions ranged from ° to 70°, whereas for lucerne, the leaf angle was nearly parallel to incident light at 85°. Leaf water-use efficiency, relative leaf water content and leaf retention were higher for the tedera accessions than for lucerne in February. These results highlight the superior drought resistance of tedera compared with lucerne. The reduction in gs over the day in tedera shows the capacity of this species to reduce water loss quickly when conditions for CO2 fixation relative to water loss are highly unfavourable. The high retention of leaves in summer by tedera is a valuable trait for a perennial pasture plant in Mediterranean environments. Leaf folding, combined with effective stomatal control in summer, provides tedera with a set of physiological responses that confer high drought resistance.

Tradeoffs among root morphology, exudation and mycorrhizal symbioses for phosphorus‐acquisition strategies of 16 crop species

Publisher: Wiley

Date: 30-04-2019

DOI: 10.1111/NPH.15833

Abstract: Plant roots exhibit erse root functional traits to enable soil phosphorus (P) acquisition, including changes in root morphology, root exudation and mycorrhizal symbioses. Yet, whether these traits are differently coordinated among crop species to enhance P acquisition is unclear. Here, eight root functional traits for P acquisition were characterized in 16 major herbaceous crop species grown in a glasshouse under limiting and adequate soil P availability. We found substantial interspecific variation in root functional traits among species. Those with thinner roots showed more root branching and less first-order root length, and had consistently lower colonization by arbuscular mycorrhizal fungi (AMF), fewer rhizosheath carboxylates and reduced acid phosphatase activity. In response to limiting soil P, species with thinner roots showed a stronger response in root branching, first-order root length and specific root length of the whole root system, Conversely, species with thicker roots exhibited higher colonization by AMF and/or more P-mobilizing exudates in the rhizosheath. We conclude that, at the species level, tradeoffs occur among the three groups of root functional traits we examined. Root diameter is a good predictor of the relative expression of these traits and how they change when P is limiting.

Intrinsic capacity for nutrient foraging predicts critical external phosphorus requirement of 12 pasture legumes

Publisher: CSIRO Publishing

Date: 2018

DOI: 10.1071/CP17276

Abstract: The mainstream pasture legume species such as Trifolium subterraneum, T. repens and annual Medicago spp. used in the temperate pasture systems of southern Australia have high critical external requirements for phosphorus (P) (i.e. P required to achieve 90% of maximum yield). This work aimed to identify alternative pasture legume species that could be used in systems with lower P input. Shoot and root biomass of 12 species of pasture legume was measured in response to seven rates of P applied to the top 48 mm of soil in a pot experiment. Most species had maximum yields similar to T. subterraneum, but some required only one-third of the applied P to achieve this. The critical external P requirement of the species, ranked from lowest to highest, was as follows: Ornithopus compressus = O. sativus Biserrula pelecinus T. michelianum = T. vesiculosum = T. glanduliferum T. hirtum = Medicago truncatula = T. purpureum = T. incarnatum T. spumosum = T. subterraneum. An ability to maximise soil exploration through a combination of high root-length density, high specific root length and long root hairs (i.e. a large specific root-hair-cylinder volume) was associated with a low critical external P requirement. The results indicate that Ornithopus spp. could be used to achieve productive, low P-input pasture systems.

Location and quantification of phosphorus and other elements in fully hydrated, soil‐grown arbuscular mycorrhizas: a cryo‐analytical scanning electron microscopy study

Publisher: Wiley

Date: 17-10-2003

DOI: 10.1046/J.1469-8137.2003.00884.X

Vellozioid roots allow for habitat specialization among rock‐ and soil‐dwelling Velloziaceae in campos rupestres

Publisher: Wiley

Date: 14-12-2019

DOI: 10.1111/1365-2435.13479

A significant increase in rhizosheath carboxylates and greater specific root length in response to terminal drought is associated with greater relative phosphorus acquisition in chickpea

Publisher: Springer Science and Business Media LLC

Date: 26-11-2021

DOI: 10.1007/S11104-020-04776-X

Accumulation of phosphorus and calcium in different cells protects the phosphorus-hyperaccumulator Ptilotus exaltatus from phosphorus toxicity in high-phosphorus soils

Publisher: Elsevier BV

Date: 02-2021

DOI: 10.1016/J.CHEMOSPHERE.2020.128438

Phosphorus uptake and toxicity are delimited by mycorrhizal symbiosis in P-sensitive Eucalyptus marginata but not in P-tolerant Acacia celastrifolia

Publisher: Oxford University Press (OUP)

Date: 21-08-2022

DOI: 10.1093/AOBPLA/PLAC037

Abstract: Many plant species from regions with ancient, highly weathered nutrient-depleted soils have specialized adaptations for acquiring phosphorus (P) and are sensitive to excess P supply. Mycorrhizal associations may regulate P uptake at high external P concentrations, potentially reducing P toxicity. We predicted that excess P application will negatively impact species from the nutrient-depleted Jarrah forest of Western Australia and that mycorrhizal inoculation will reduce P toxicity by regulating P uptake. For seedlings of the N2-fixing legume Acacia celastrifolia and the tree species Eucalyptus marginata, we measured growth at P concentrations of 0–90 mg kg−1 soil and in relation to inoculation with the arbuscular mycorrhizal fungus (AMF) Rhizophagus irregularis. Non-inoculated A. celastrifolia maintained leaf P concentrations at & mg g−1 dry mass (DM) across the range of external P concentrations. However, for non-inoculated E. marginata, as external P concentrations increased, leaf P also increased, reaching & mg g−1 DM at 30 mg P kg−1 soil. Acacia celastrifolia DM increased with increasing external P concentrations, while E. marginata DM was maximal at 15 mg P kg−1 soil, declining at higher external P concentrations. Neither DM nor leaf P of A. celastrifolia was affected by inoculation with AMF. For E. marginata, even at 90 mg P kg−1 soil, inoculation with AMF resulted in leaf P remaining & mg g−1 DM, and DM being maintained. These data strengthen the evidence base that AMF may not only facilitate P uptake at low external P concentrations, but are also important for moderating P uptake at elevated external P concentrations and maintaining plant P concentrations within a relatively narrow concentration range.

Production, survival and nutritive value of the perennial legumes Dorycnium hirsutum and D. rectum subjected to different cutting heights

Publisher: Wiley

Date: 20-02-2006

DOI: 10.1111/J.1365-2494.2006.00508.X

Adaptive shoot and root responses collectively enhance growth at optimum temperature and limited phosphorus supply of three herbaceous legume species

Publisher: Oxford University Press (OUP)

Date: 29-07-2012

DOI: 10.1093/AOB/MCS166

Enhanced nodulation and phosphorus acquisition from sparingly-soluble iron phosphate upon treatment with arbuscular mycorrhizal fungi in chickpea

Publisher: Wiley

Date: 28-02-2023

DOI: 10.1111/PPL.13873

Abstract: The coordination/trade‐off among below‐ground strategies for phosphorus (P) acquisition, including root morphology, carboxylate exudation and colonisation by arbuscular mycorrhizal fungi (AMF), is not well understood. This is the first study investigating the relationships between root nodulation, morphology, carboxylates and colonisation by an indigenous community of AMF under varying P levels and source. Two chickpea genotypes with contrasting amounts of rhizosheath carboxylates were grown in pots at six P levels (from 0 to 160 μg g −1 ) as KH 2 PO 4 (KP, highly soluble) or FePO 4 (FeP, sparingly soluble), with or without AMF (±AMF) treatment. Under both FeP and KP, the presence of AMF inhibited shoot growth and shoot branching, decreased total root length and specific root length, increased mean root diameter and root tissue density and reduced carboxylates. However, the role of AMF in acquiring P differed between the two P sources, with the enhanced P acquisition under FeP while not under KP. Co‐inoculation of AMF and rhizobia enhanced nodulation under FeP, but not under KP. Our results suggest that the effects of AMF on shoot branching were mediated by cytokinins as the reduced shoot branching in FeP40 and KP40 under +AMF relative to −AMF coincided with a decreased concentration of cytokinins in xylem sap for both genotypes.

Niche differentiation of Mucoromycotinian and Glomeromycotinian arbuscular mycorrhizal fungi along a 2-million-year soil chronosequence

Publisher: Springer Science and Business Media LLC

Date: 11-05-2023

DOI: 10.1007/S00572-023-01111-X

Abstract: Current literature suggests ecological niche differentiation between co-occurring Mucoromycotinian arbuscular mycorrhizal fungi (M-AMF) and Glomeromycotinian AMF (G-AMF), but experimental evidence is limited. We investigated the influence of soil age, water availability (wet and dry), and plant species (native Microlaena stipoides and exotic Trifolium subterraneum ) on anatomical root colonisation and DNA profiles of M-AMF and G-AMF under glasshouse conditions. We grew seedlings of each species in soils collected from the four stages of a soil chronosequence, where pH decreases from the youngest to oldest stages, and phosphorus (P) is low in the youngest and oldest, but high in the intermediate stages. We scored the percentage of root length colonised and used DNA metabarcoding to profile fungal richness and community composition associated with treatment combinations. Soil age, water availability, and plant species were important influencers of root colonisation, although no M-AMF were visible following staining of M. stipoides roots. Soil age and host plant influenced fungal richness and community composition. However, response to soil age, potential host species, and water availability differed between M-AMF and G-AMF. Root colonisation of T. subterraneum by M-AMF and G-AMF was inversely correlated with soil P level. Community composition of M-AMF and G-AMF was structured by soil age and, to a lesser extent, plant species. Richness of M-AMF and G-AMF was negatively, and positively, correlated with available P, respectively. These findings are experimental evidence of ecological niche differentiation of M-AMF and G-AMF and invite further exploration into interactive effects of abiotic and biotic factors on their communities along successional trajectories.

Evidence for Niche Differentiation in the Environmental Responses of Co-occurring Mucoromycotinian Fine Root Endophytes and Glomeromycotinian Arbuscular Mycorrhizal Fungi

Publisher: Springer Science and Business Media LLC

Date: 03-11-2020

DOI: 10.1007/S00248-020-01628-0

Phosphorus- and nitrogen-acquisition strategies in two Bossiaea species (Fabaceae) along retrogressive soil chronosequences in south-western Australia

Publisher: Wiley

Date: 30-03-2018

DOI: 10.1111/PPL.12704

Abstract: During long-term ecosystem development and its associated decline in soil phosphorus (P) availability, the abundance of mycorrhizal plant species declines at the expense of non-mycorrhizal species with root specialisations for P-acquisition, such as massive exudation of carboxylates. Leaf manganese (Mn) concentration has been suggested as a proxy for such a strategy, Mn concentration being higher in non-mycorrhizal plants that release carboxylates than in mycorrhizal plants. Shifts in nitrogen (N)-acquisition strategies also occur nodulation in legumes is expected at low N availability, when sufficient P is available. We investigated whether two congeneric legume species (Bossiaea linophylla and Bossiaea eriocarpa) occurring along two long-term chronosequences on the south-western Australian coast and grown in a glasshouse at varying N and P supply exhibited plasticity in nutrient-acquisition strategies. We hypothesised that the shifts in nutrient limitation and nutrient-acquisition strategies at the community level would also be found at the species level. Leaf N: P ratios and the responses to nutrient availability suggested that growth of both species exhibited P-limitation in all treatments, due to the very high leaf [N] of legumes afforded by symbiotic N-fixation. Mycorrhizal colonisation was not greater at higher P supply, and root exudation of carboxylates was not stimulated at low P supply both were unrelated to leaf [Mn]. However, nodule production declined with increasing N supply. We conclude that intraspecific variation in nutrient-acquisition and use is low in these species, and that the variation at the community level, observed in previous studies, is likely driven by high-species turnover.

Contrasting responses to drought stress in herbaceous perennial legumes

Publisher: Springer Science and Business Media LLC

Date: 15-07-2011

DOI: 10.1007/S11104-011-0904-X

Break crops and rotations for wheat

Publisher: CSIRO Publishing

Date: 2015

DOI: 10.1071/CP14252

Abstract: Wheat crops usually yield more when grown after another species than when grown after wheat. Quantifying the yield increase and explaining the factors that affect the increase will assist farmers to decide on crop sequences. This review quantifies the yield increase, based on comparisons of wheat growing after a break crop with wheat after wheat. The mean increase in wheat yield varied with species of break crop, ranging from 0.5 t ha–1 after oats to 1.2 t ha–1 after grain legumes. Based on overlapping experiments, the observed ranking of break-crop species in terms of mean yield response of the following wheat crop was: oats canola ≈ mustard ≈ flax field peas ≈ faba beans ≈ chickpeas ≈ lentils ≈ lupins. The mean additional wheat yield after oats or oilseed break crops was independent of the yield level of the following wheat crop. The wheat yield response to legume break crops was not clearly independent of yield level and was relatively greater at high yields. The yield of wheat after two successive break crops was 0.1–0.3 t ha–1 greater than after a single break crop. The additional yield of a second wheat crop after a single break crop ranged from 20% of the effect on a first wheat crop after canola, to 60% after legumes. The mean yield effect on a third wheat crop was negligible, except in persistently dry conditions. The variability of the break-crop effect on the yield of a second wheat crop was larger than of a first wheat crop, particularly following canola. We discuss the responses in relation to mechanisms by which break crops affect soil and following crops. By quantifying the magnitude and persistence of break-crop effects, we aim to provide a basis for the decision to grow continuous cereal crops, strategic rotations or tactically selected break crops. In many wheat-growing areas, the large potential yield increases due to break crops are not fully exploited. Research into quantifying the net benefits of break crops, determining the situations where the benefits are greatest, and improving the benefits of break crops promises to improve the efficiency of wheat-based cropping systems.

Rhizosphere 3: where plants meet soils down-under

Publisher: Springer Science and Business Media LLC

Date: 14-08-2012

DOI: 10.1007/S11104-012-1415-0

Carbon trading for phosphorus gain: the balance between rhizosphere carboxylates and arbuscular mycorrhizal symbiosis in plant phosphorus acquisition

Publisher: Wiley

Date: 21-06-2012

DOI: 10.1111/J.1365-3040.2012.02547.X

Abstract: Two key plant adaptations for phosphorus (P) acquisition are carboxylate exudation into the rhizosphere and mycorrhizal symbioses. These target different soil P resources, presumably with different plant carbon costs. We examined the effect of inoculation with arbuscular mycorrhizal fungi (AMF) on amount of rhizosphere carboxylates and plant P uptake for 10 species of low-P adapted Kennedia grown for 23 weeks in low-P sand. Inoculation decreased carboxylates in some species (up to 50%), decreased plant dry weight (21%) and increased plant P content (23%). There was a positive logarithmic relationship between plant P content and the amount of rhizosphere citric acid for inoculated and uninoculated plants. Causality was indicated by experiments using sand where little citric acid was lost from the soil solution over 2 h and citric acid at low concentrations desorbed P into the soil solution. Senesced leaf P concentration was often low and P-resorption efficiencies reached >90%. In conclusion, we propose that mycorrhizally mediated resource partitioning occurred because inoculation reduced rhizosphere carboxylates, but increased plant P uptake. Hence, presumably, the proportion of plant P acquired from strongly sorbed sources decreased with inoculation, while the proportion from labile inorganic P increased. Implications for plant fitness under field conditions now require investigation.

Hotspots and gaps in the world collection of subterranean clover (Trifolium subterraneum L.)

Publisher: Cambridge University Press (CUP)

Date: 19-08-2014

DOI: 10.1017/S0021859614000793

Abstract: Subterranean clover ( Trifolium subterraneum L.) is the most important annual pasture legume in the winter-dominant rainfall areas of Southern Australia. Systematic germplasm collections of subterranean clover from its centre of origin have been made since the 1950s, particularly by Australian scientists, in order to broaden the genetic base of the species. The present study reports on a meta-analysis of the distribution of the world collection of subterranean clovers and their relationships to eco-geographic variables of the collection sites in their native habitat. Diversity hotspots (areas rich in number of accessions and containing a high ersity of sub-species) and also gaps (areas with particular traits un- or under-represented in collections) were identified. This was achieved using a stratified data system to evaluate eco-geographical and agro-morphological data which incorporated three tiers of information for the subterranean clover collection: (1) information from each collection site, including ecological data (2) information on the phenotypic ersity within each collection site and (3) plant agro-morphological data from each s le grown under controlled conditions. Correlations were found between some eco-geographic conditions and agronomic performance. These included correlations between latitude and flowering time, mean temperature in winter and winter productivity and precipitation in summer and seed dormancy. The present study concluded that subterranean clover versatility is greater than suggested in the past. The results of the current analysis provide a guide for future collecting missions to specific regions towards areas of maximum ersity (hotspots) and unknown ersity (gaps).

Low light availability alters root exudation and reduces putative beneficial microorganisms in seagrass roots

Publisher: Frontiers Media SA

Date: 11-01-2018

DOI: 10.3389/FMICB.2017.02667

Variation in root traits associated with nutrient foraging among temperate pasture legumes and grasses

Publisher: Wiley

Date: 30-09-2015

DOI: 10.1111/GFS.12199

Agricultural land-use favours Mucoromycotinian, but not Glomeromycotinian, arbuscular mycorrhizal fungi across ten biomes

Publisher: Wiley

Date: 02-11-2021

DOI: 10.1111/NPH.17780

Abstract: Globally, agricultural land‐use negatively affects soil biota that contribute to ecosystem functions such as nutrient cycling, yet arbuscular mycorrhizal fungi (AMF) are promoted as essential components of agroecosystems. Arbuscular mycorrhizal fungi include Glomeromycotinian AMF (G‐AMF) and the arbuscule‐producing fine root endophytes, recently re‐classified into the Endogonales order within Mucoromycotina. The correct classification of Mucoromycotinian AMF (M‐AMF) and the availability of new molecular tools can guide research to better the understanding of their ersity and ecology. To investigate the impact on G‐AMF and M‐AMF of agricultural land‐use at a continental scale, we s led DNA from paired farm and native sites across 10 Australian biomes. Glomeromycotinian AMF were present in both native and farm sites in all biomes. Putative M‐AMF were favoured by farm sites, rare or absent in native sites, and almost entirely absent in tropical biomes. Temperature, rainfall, and soil pH were strong drivers of richness and community composition of both groups, and plant richness was an important mediator. Both fungal groups occupy different, but overlapping, ecological niches, with M‐AMF thriving in temperate agricultural landscapes. Our findings invite exploration of the origin and spread of M‐AMF and continued efforts to resolve the phylogeny of this newly reclassified group of AMF.

Commensalism in an agroecosystem: hydraulic redistribution by deep-rooted legumes improves survival of a droughted shallow-rooted legume companion

Publisher: Wiley

Date: 18-01-2013

DOI: 10.1111/PPL.12020

Abstract: We investigated commensalism of water use among annual shallow-rooted and perennial deep-rooted pasture legumes by examining the effect of hydraulic lift by Cullen pallidum (N.T.Burb.) J.W.Grimes and Medicago sativa on growth, survival and nutrient uptake of Trifolium subterraneum L. A vertically split-root design allowed separate control of soil water in top and bottom soil. Thirty-five days after watering ceased in the top tube, but soil remained at field capacity in the bottom tube, an increase in shallow soil water content by hydraulic lift was 5.6 and 5.9 g kg(-1) soil overnight for C. pallidum and M. sativa, respectively. Trifolium subterraneum in this treatment maintained higher leaf water potentials (with M. sativa) or exhibited a slower decline (with C. pallidum) than without companion perennial plants and shoot biomass of T. subterraneum was 56% (with C. pallidum) and 67% (with M. sativa) of that when both top and bottom tubes were at field capacity. Uptake of rubidium (a potassium analog) and phosphorus by T. subterraneum was not facilitated by hydraulic lift. Interestingly, phosphorus content was threefold greater, and shoot biomass 1.5-3.3-fold greater when T. subterraneum was interplanted with C. pallidum compared with M. sativa, although dry weight of C. pallidum was much greater than that of M. sativa. This study showed that interplanting with deep-rooted perennial legumes has benefited the survival of T. subterraneum.

Prioritisation of novel pasture species for use in water-limited agriculture: a case study of Cullen in the Western Australian wheatbelt

Publisher: Springer Science and Business Media LLC

Date: 12-05-2011

DOI: 10.1007/S10722-010-9567-3

Pronounced surface stratification of soil phosphorus, potassium and sulfur under pastures upstream of a eutrophic wetland and estuarine system

Publisher: CSIRO Publishing

Date: 2017

DOI: 10.1071/SR16144

Abstract: High concentrations of nutrients in surface soil present a risk of nutrient movement into waterways through surface water pathways and leaching. Phosphorus (P) is of particular concern because of its role in aquatic system eutrophication. We measured nutrients under annual pastures on a beef farm and a dairy farm in the Peel–Harvey catchment, Western Australia. Soils were s led in 10-mm increments to 100mm depth in March, June and September. Plant litter contained approximately 300–550mg kg–1 Colwell-extractable P. Extractable soil P was strongly stratified, being approximately 100–225mg kg–1 (dairy) and 50–110mg kg–1 (beef) in the top 10mm and mg kg–1 at 40–50mm depth. Total P and extractable potassium were also highly stratified, whereas sulfur was less strongly stratified. Shoot nutrient concentrations indicated that nitrogen was often limiting and sulfur was sometimes limiting for pasture growth: concentrations of P were often much greater than required for adequate growth ( mg g–1). We conclude that high P concentrations at the soil surface and in litter and shoots are a source of risk for movement of P from farms into waterways in the Peel–Harvey catchment.

Do arbuscular mycorrhizas or heterotrophic soil microbes contribute toward plant acquisition of a pulse of mineral phosphate?

Publisher: Springer Science and Business Media LLC

Date: 20-07-2013

DOI: 10.1007/S11104-013-1838-2

Fine root endophytes under scrutiny: a review of the literature on arbuscule-producing fungi recently suggested to belong to the Mucoromycotina

Publisher: Springer Science and Business Media LLC

Date: 07-06-2017

DOI: 10.1007/S00572-017-0782-Z

Abstract: Fine root endophytes (FRE) are arbuscule-forming fungi presently considered as a single species-Glomus tenue in the Glomeromycota (Glomeromycotina)-but probably belong within the Mucoromycotina. Thus, FRE are the only known arbuscule-forming fungi not within the arbuscular mycorrhizal fungi (AMF Glomeromycotina) as currently understood. Phylogenetic differences between FRE and AMF could reflect ecological differences. To synthesize current ecological knowledge, we reviewed the literature on FRE and identified 108 papers that noted the presence of FRE and, in some, the colonization levels for FRE or AMF (or both). We categorized these records by geographic region, host-plant family and environment (agriculture, moderate-natural, low-temperature, high-altitude and other) and determined their influence on the percentage of root length colonized by FRE in a meta-analysis. We found that FRE are globally distributed, with many observations from Poaceae, perhaps due to grasses being widely distributed. In agricultural environments, colonization by FRE often equalled or exceeded that of AMF, particularly in Australasia. In moderate-natural and high-altitude environments, average colonization by FRE (~10%) was lower than that of AMF (~35%), whereas in low-temperature environments, colonization was similar (~20%). Several studies suggested that FRE can enhance host-plant phosphorus uptake and growth, and may be more resilient than AMF to environmental stress in some host plants. Further research is required on the functioning of FRE in relation to the environment, host plant and co-occurring AMF and, in particular, to examine whether FRE are important for plant growth in stressful environments. Targeted molecular primers are urgently needed for further research on FRE.

Effects of leaf development and phosphorus supply on the photosynthetic characteristics of perennial legume species with pasture potential: modelling photosynthesis with leaf development

Publisher: CSIRO Publishing

Date: 2010

DOI: 10.1071/FP09284

Abstract: Age-dependent changes in leaf photosynthetic characteristics (i.e. parameters of the light response curve (maximum photosynthetic rate (Pmax), quantum yield (Φ) and the convexity parameter (θ)), stomatal conductance (gs) and dark respiration rate (Rd)) of an exotic perennial legume, Medicago sativa L. (lucerne), and two potential pasture legumes native to Australia, Cullen australasicum (Schltdl.) J.W. Grime and Cullen pallidum A. Lee, grown in a glasshouse for 5 months at two phosphorus (P) levels (3 (P3) and 30 (P30) mg P kg–1 dry soil) were tested. Leaf appearance rate and leaf area were lower at P3 than at P30 in all species, with M. sativa being the most sensitive to P3. At any leaf age, photosynthetic characteristics did not differ between P treatments. However, Pmax and gs for all the species and Φ for Cullen species increased until full leaf expansion and then decreased. The convexity parameter, θ, did not change with leaf age, whereas Rd decreased. The estimates of leaf net photosynthetic rate (Pleaf) obtained through simulations at variable Pmax and Φ were lower during early and late leaf developmental stages and at lower light intensities than those obtained when Φ was assumed to be constant (e.g. for a horizontally placed leaf, during the 1500°C days developmental period, 3 and 19% reduction of Pleaf at light intensities of 1500 and 500 µmol m–2 s–1, respectively). Therefore, developmental changes in leaf photosynthetic characteristics should be considered when estimating and simulating Pleaf of these pasture species.

Critical phosphorus requirements of Trifolium species: The importance of root morphology and root acclimation in response to phosphorus stress

Publisher: Wiley

Date: 30-07-2021

DOI: 10.1111/PPL.13500

Abstract: Differences in root morphology and acclimation to low‐phosphorus (P) soil were examined among eight legume species from the Trifolium Section Tricocephalum to understand how these root attributes determine P acquisition. Ornithopus sativus was included as a highly P‐efficient benchmark species. Plants were grown as microswards in pots with five rates of P supplied in a topsoil layer to mimic uneven P distribution within a field soil profile. Topsoil and subsoil roots were harvested separately to enable measurement of the nutrient‐foraging responses. Critical P requirement (lowest P supply for maximum yield) varied over a threefold range, reflecting differences in root morphology and acclimation of nutrient‐foraging roots to P stress. Among the species, there was a 3.2‐fold range in root length density, a 1.7‐fold range in specific root length, and a 2.1‐fold range in root hair length. O . sativus had the lowest critical P requirement, displayed a high root length density, the highest specific root length, and the longest root hairs. Acquisition of P from P‐deficient soil was facilitated by development of a large root hair cylinder (i.e. a large root–soil interface). This, in turn, was determined by the intrinsic root morphology attributes of each genotype, and the plasticity of its root morphology response to internal P stress. Root acclimation in low‐P soil by all species was mostly associated with preferential allocation of mass to nutrient‐foraging roots. Only O . sativus and four of the Trifolium species adjusted specific root length beneficially, and only O . sativus increased its root hair length in low‐P soil.

Amelioration of root disease of subterranean clover (Trifolium subterraneum) by mineral nutrients

Publisher: CSIRO Publishing

Date: 2012

DOI: 10.1071/CP12239

Abstract: Subterranean clover (Trifolium subterraneum) is a key pasture legume across southern Australia and elsewhere. Decline in subterranean clover pastures was first recognised in Australia during the 1960s and manifests as an increase in weeds and a decrease in desirable legume species. While both root disease and poor nutrition contribute to subterranean clover pasture decline, the relationships between root disease and nutrition have not been determined. The objective of this study was to define these relationships. Field experiments were undertaken to determine the nutritional and pathogen status of soils and subterranean clover from three Western Australian field sites. Subsequently, controlled environment experiments were undertaken to determine the relative severities of tap and lateral root disease and growth of plants when soil cores taken from these three field sites were amended with a complete nutrient solution or a range of in idual macro- or micronutrient treatments. Application of a ‘Hoaglands’ complete nutrient solution decreased the severity of tap root disease by an average of 45% and lateral root disease by 32%. Amendment with K alone reduced the severity of tap root disease an average of 32% while the application of N alone reduced the severity of tap root disease by 33% and lateral root disease by 27%. Application of Hoaglands, K, N or Zn increased shoot and root dry weight, while Mo only increased shoot dry weight. This is the first report to show that mineral nutrients can substantially ameliorate root disease in subterranean clover. The results demonstrate that while root disease limits plant growth, improvement in the nutritional status of nutrient-impoverished soils can significantly reduce root disease. There is significant potential to incorporate nutrient amendments into an integrated and more sustainable approach to better manage root disease and to increase productivity of pasture legumes where soils are inherently nutrient deficient in one or more nutrients.

Sample storage conditions alter colonisation structures of arbuscular mycorrhizal fungi and, particularly, fine root endophyte

Publisher: Springer Science and Business Media LLC

Date: 04-04-2017

DOI: 10.1007/S11104-016-2867-4

Brassica crops stimulate soil mineral N accumulation

Publisher: CSIRO Publishing

Date: 2006

DOI: 10.1071/SR05143

Abstract: The impact of Brassica crops and their tissues on accumulation of mineral N in soil was examined in the field and in laboratory incubation experiments. Mineral N accumulation over the summer fallow increased by an additional 39–49 kg/ha in the top 0.10 m of soil following brassicas compared with wheat at 2 sites. At a third site there was no increase in the top 0.10 m, but this was possibly due to leaching, as a 21–39 kg/ha increase was detected over the 1.50 m profile. The accumulation of mineral N in soil collected after harvest of canola crops and incubated in the laboratory was double that of soil collected after non-Brassica crops. This outcome was not evident in soil collected when crops were flowering, only occurred in the top 0.05 m of soil, and did not persist beyond week 3 of the incubation. In further laboratory incubations using tissues from wheat and a range of brassicas matched for C : N ratio but differing in glucosinolate concentration, Brassica root tissues initially immobilised, and later released, mineral N at a greater rate than wheat root tissues. These results suggest that enhanced accumulation of mineral N following Brassica crops compared with cereal crops is unlikely to be due to biofumigation of the soil microbial community. Shifts in the composition of the soil microbial community and differences in the chemical constituents of root tissues and in above-ground crop residue inputs may instead be responsible.

Phosphate fertiliser alters carboxylates and bacterial communities in sweet potato (Ipomoea batatas (L.) Lam.) rhizosheaths

Publisher: Springer Science and Business Media LLC

Date: 08-2020

DOI: 10.1007/S11104-020-04646-6

Diversity for morphological traits, flowering time and leaf isoflavone content among ecotypes of

Publisher: CSIRO Publishing

Date: 12-2021

DOI: 10.1071/CP21226

Abstract: Trifolium subterraneum L. subsp. yanninicum is a pasture legume that is widely grown in medium and high rainfall areas of southern Australia and shows waterlogging tolerance. This study investigated ersity within subsp. yanninicum corresponding to eco-geographic variables, which may help to identify adapted parents with new traits for genetic improvement. Diversity for 10 morphological traits, flowering time and leaf isoflavone content was investigated using 108 ecotypes derived from wild Mediterranean populations and 10 cultivars, grown as spaced plants. Among the ecotypes, the range of flowering time was 94–149 days after sowing, and contents of formononetin, genistein and biochanin A were 0.05–1.38%, 0.73–2.33% and 0.15–2.10% of dry matter, respectively. Leaf markings also varied considerably. Leaf size and petiole length were correlated at each growth stage. Later flowering genotypes had larger leaves, longer petioles, longer internodes and thicker stems at flowering, but smaller leaves and shorter petioles at both 63 and 88 days after sowing. Contents of genistein and biochanin A were unrelated, but both were negatively associated with formononetin. Flowering time had a weak positive influence on genistein and biochanin A, but a weak negative influence on formononetin. All traits among the ecotypes (except stem diameter and leaf mark crescent size) were significantly correlated with at least one of 22 eco-geographic variables from their collection sites. Precipitation and altitude were more influential than temperature. The study found sufficient ersity to broaden the narrow genetic base of current subsp. yanninicum cultivars however, other agronomically important traits also need to be considered. Further ersity may result from targeted collection, particularly in areas not represented in annual legume genebanks.

Statistical emulators of a plant growth simulation model

Publisher: Inter-Research Science Center

Date: 06-02-2013

DOI: 10.3354/CR01138

Root distributions of Australian herbaceous perennial legumes in response to phosphorus placement

Publisher: CSIRO Publishing

Date: 2006

DOI: 10.1071/FP06176

Abstract: Many Australian plant species have specific root adaptations for growth in phosphorus-impoverished soils, and are often sensitive to high external P concentrations. The growth responses of native Australian legumes in agricultural soils with elevated P availability in the surface horizons are unknown. The aim of these experiments was to test the hypothesis that increased P concentration in surface soil would reduce root proliferation at depth in native legumes. The effect of P placement on root distribution was assessed for two Australian legumes, Kennedia prorepens F. Muell. and Lotus australis Andrews, and the exotic Medicago sativa L. Three treatments were established in a low-P loam soil: amendment of 0.15 g mono-calcium phosphate in either (i) the top 50 mm (120 µg P g–1) or (ii) the top 500 mm (12 µg P g–1) of soil, and an unamended control. In the unamended soil M. sativa was shallow rooted, with 58% of the root length of in the top 50 mm. K. prorepens and L. australis had a more even distribution down the pot length, with only 4 and 22% of their roots in the 0–50 mm pot section, respectively. When exposed to amendment of P in the top 50 mm, root length in the top 50 mm increased 4-fold for K. prorepens and 10-fold for M. sativa, although the pattern of root distribution did not change for M. sativa. L. australis was relatively unresponsive to P additions and had an even distribution of roots down the pot. Shoot P concentrations differed according to species but not treatment (K. prorepens 2.1 mg g–1, L. australis 2.4 mg g–1, M. sativa 3.2 mg g–1). Total shoot P content was higher for K. prorepens than for the other species in all treatments. In a second experiment, mono-ester phosphatases were analysed from 1-mm slices of soil collected directly adjacent to the rhizosphere. All species exuded phosphatases into the rhizosphere, but addition of P to soil reduced phosphatase activity only for K. prorepens. Overall, high P concentration in the surface soil altered root distribution, but did not reduce root proliferation at depth. Furthermore, the Australian herbaceous perennial legumes had root distributions that enhanced P acquisition from low-P soils.

Comparative water use by Dorycnium hirsutum-, lucerne-, and annual-based pastures in the Western Australian wheatbelt

Publisher: CSIRO Publishing

Date: 2006

DOI: 10.1071/AR05409

Abstract: Dryland salinity in southern Australia has been caused by inadequate water use by annual crops and pastures. The purpose of this study was to compare the water use of annual pastures and Medicago sativa L. (lucerne) with Dorycnium hirsutum (L.) Ser., a potential new perennial forage species. The soil water dynamics under bare ground, annual legume-, lucerne-, and D. hirsutum-based pastures were compared at 2 sites in the low- (Merredin) and medium- (New Norcia) rainfall wheatbelt of Western Australia between September 2002 and February 2005. Soil under D. hirsutum was drier than under annual pastures by 8–23 mm in Year 1, 43–57 mm in Year 2, and 81 mm in Year 3. Lucerne used little additional water ( mm, n.s.) compared with D. hirsutum and profile soil water content was similar under both species throughout the experiment. At Merredin, annual pastures used water to a depth of 1.0 m, whereas under both D. hirsutum and lucerne in the first 3 years after establishment the successive maximum depth of water use was 1.0, 1.8, and 2.2 m. At New Norcia, additional soil water was extracted by lucerne and D. hirsutum at depths .0 m and no difference between treatments was detected below 1.0 m. Biomass of D. hirsutum pasture harvested in autumn contained minimal annual components and was 15–50% of that produced by lucerne- or annual legume-based pastures. D. hirsutum and lucerne plant density declined each summer (25–80%), but D. hirsutum density was lower than lucerne due to poorer establishment. Nonetheless, the comparable water use of lucerne and D. hirsutum suggests that D. hirsutum could make reductions in recharge similar to those of lucerne in the Western Australian wheatbelt.

A review of germination and early growth as a proxy for plant fitness under petrogenic contamination — knowledge gaps and recommendations

Publisher: Elsevier BV

Date: 12-2017

DOI: 10.1016/J.SCITOTENV.2017.02.179

Abstract: Germination-an important stage in the life cycle of plants-is susceptible to the presence of soil contaminants. Since the early 1990s, the use of germination tests to screen multiple plant species to select candidates for phytoremediation has received much attention. This is due to its inexpensive methodology and fast assessment relative to greenhouse or field growth studies. Surprisingly, no comprehensive synthesis is available of these studies in the scientific literature. As more plant species are added to phytoremediation databases, it is important to encapsulate the knowledge thus far and revise protocols. In this review, we have summarised previously-documented effects of petroleum hydrocarbons on germination and seedling growth. The methods and materials of previous studies are presented in tabulated form. Common practice includes the use of cellulose acetate filter paper, plastic Petri dishes, and low numbers of seeds and replicates. A general bias was observed for the screening of cultivated crops as opposed to native species, even though the latter may be better suited to site conditions. The relevance of germination studies as important ecotoxicological tools is highlighted with the proposed use of root imaging software. Screening of novel plant species, particularly natives, is recommended with selection focussed on (i) species phylogeny, (ii) plant morphological and functional traits, and (iii) tolerance towards harsh environmental stresses. Recommendations for standardised protocols for germination and early growth monitoring are made in order to improve the robustness of statistical modelling and species selection in future phytoremediation evaluations and field programs.

In addition to foliar manganese concentration, both iron and zinc provide proxies for rhizosheath carboxylates in chickpea under low phosphorus supply

Publisher: Springer Science and Business Media LLC

Date: 04-05-2021

DOI: 10.1007/S11104-021-04988-9

Phosphorus nutrition of proteaceae in severely phosphorus-impoverished soils: Are there lessons to be learned for future crops?

Publisher: Oxford University Press (OUP)

Date: 15-04-2011

DOI: 10.1104/PP.111.174318

Peppermint trees shift their phosphorus-acquisition strategy along a strong gradient of plant-available phosphorus by increasing their transpiration at very low phosphorus availability

Publisher: Springer Science and Business Media LLC

Date: 18-09-2017

DOI: 10.1007/S00442-017-3961-X

Abstract: Some plant species use different strategies to acquire phosphorus (P) dependent on environmental conditions, but studies investigating the relative significance of P-acquisition strategies with changing P availability are rare. We combined a natural P availability gradient and a glasshouse study with 10 levels of P supplies to investigate the roles of rhizosphere carboxylates and transpiration-driven mass flow in P acquisition by Agonis flexuosa. Leaf P concentrations of A. flexuosa decreased and leaf manganese (Mn) concentrations increased with decreasing soil P concentration along a dune chronosequence. In the glasshouse, in response to decreasing P supply, shoot growth and root length decreased, leaf P and Mn concentrations decreased, rhizosphere carboxylates decreased, transpiration rate and transpiration ratio increased and the percentage of root length colonized by arbuscular mycorrhizal fungi was unchanged. Although it was proved leaf Mn concentration was a good proxy for rhizosphere carboxylate amounts in the glasshouse study, the enhanced plant P acquisition at low P supply was related to transpiration-induced mass flow rather than carboxylates. We deduced that the higher leaf Mn concentrations in low soil P availability of the field were likely a result of increased mass flow. In summary, as soil P availability declined, A. flexuosa can shift its P-acquisition strategy away from a mycorrhizal mode towards one involving increased mass flow.

Differences in foliar phosphorus fractions, rather than in cell-specific phosphorus allocation, underlie contrasting photosynthetic phosphorus use efficiency among chickpea genotypes

Publisher: Oxford University Press (OUP)

Date: 28-12-2023

DOI: 10.1093/JXB/ERAC519

Abstract: Although significant intraspecific variation in photosynthetic phosphorus (P) use efficiency (PPUE) has been shown in numerous species, we still know little about the biochemical basis for differences in PPUE among genotypes within a species. Here, we grew two high PPUE and two low PPUE chickpea (Cicer arietinum) genotypes with low P supply in a glasshouse to compare their photosynthesis-related traits, total foliar P concentration ([P]) and chemical P fractions (i.e. inorganic P (Pi), metabolite P, lipid P, nucleic acid P, and residual P). Foliar cell-specific nutrient concentrations including P were characterized using elemental X-ray microanalysis. Genotypes with high PPUE showed lower total foliar [P] without slower photosynthetic rates. No consistent differences in cellular [P] between the epidermis and mesophyll cells occurred across the four genotypes. In contrast, high PPUE was associated with lower allocation to Pi and metabolite P, with PPUE being negatively correlated with the percentage of these two fractions. Furthermore, a lower allocation to Pi and metabolite P was correlated with a greater allocation to nucleic acid P, but not to lipid P. Collectively, our results suggest that a different allocation to foliar P fractions, rather than preferential P allocation to specific leaf tissues, underlies the contrasting PPUE among chickpea genotypes.

Reduced growth of autumn-sown wheat in a low-P soil is associated with high colonisation by arbuscular mycorrhizal fungi

Publisher: Springer Science and Business Media LLC

Date: 03-2005

DOI: 10.1007/S11104-004-1611-7

Above- and below-ground interactions of grass and pasture legume species when grown together under drought and low phosphorus availability

Publisher: Springer Science and Business Media LLC

Date: 05-03-2011

DOI: 10.1007/S11104-011-0754-6

Severity of root rot in mature subterranean clover and associated fungal pathogens in the wheatbelt of Western Australia

Publisher: CSIRO Publishing

Date: 2009

DOI: 10.1071/CP08187

Abstract: Pasture decline is considered to be a serious challenge to agricultural productivity of subterranean clover across southern Australia. Root disease is a significant contributing factor to pasture decline. However, root disease assessments are generally carried out in the early part of the growing season and in areas predominantly sown to permanent pastures. For this reason, in spring 2004, a survey was undertaken to determine the severity of root disease in mature subterranean clover plants in pastures located in the wheatbelt of Western Australia. DNA-based soil assays were used to estimate population density in the soil of a variety of soil-borne pathogens known to commonly occur in the Mediterranean-type environments of southern Australia. The relationships between severity of disease on tap and lateral roots and root diameter, root length, nodulation, and total rainfall were determined. The survey showed, for the first time, that severe root disease is widespread in spring across the wheatbelt of Western Australia. There was a positive correlation between rainfall and tap root disease, and between tap root disease and average root diameter of the entire root system. Despite the high levels of root disease present across the sites, the DNA of most root disease pathogens assayed was detected in trace concentrations. Only Pythium Clade F showed high DNA concentrations in the soil. DNA concentrations in the soil, in particular for Phytophthora clandestina and Rhizoctonia solani AG 2.1 and AG 2.2, were higher in the smaller autumn s ling in 2006. This study suggests that the productivity of subterranean clover-based pastures is severely compromised by root rot diseases throughout the growing season in the wheatbelt of Western Australia.

Development, characterization and transferability of microsatellite markers for Cullen australasicum (Leguminosae)

Publisher: Springer Science and Business Media LLC

Date: 05-03-2009

DOI: 10.1007/S10592-009-9820-5

The carboxylate composition of rhizosheath and root exudates from twelve species of grassland and crop legumes with special reference to the occurrence of citramalate

Publisher: Springer Science and Business Media LLC

Date: 02-01-2018

DOI: 10.1007/S11104-017-3534-0

The diversity of arbuscular mycorrhizas of selected Australian Fabaceae

Publisher: Informa UK Limited

Date: 07-2008

DOI: 10.1080/11263500802151124

Root growth response of serradella species to aluminium in solution culture and soil

Publisher: Wiley

Date: 03-2021

DOI: 10.1111/GFS.12528

Unwrapping the rhizosheath

Publisher: Springer Science and Business Media LLC

Date: 27-07-2017

DOI: 10.1007/S11104-017-3358-Y

Arbuscular mycorrhizae in wheat and field pea crops on a low P soil: increased Zn-uptake but no increase in P-uptake or yield

Publisher: Springer Science and Business Media LLC

Date: 2003

DOI: 10.1023/A:1022839930134

Differences in nutrient foraging among Trifolium subterraneum cultivars deliver improved P-acquisition efficiency

Publisher: Springer Science and Business Media LLC

Date: 09-01-2018

DOI: 10.1007/S11104-017-3511-7

Perennial legumes native to Australia - a preliminary investigation of nutritive value and response to cutting

Publisher: CSIRO Publishing

Date: 2007

DOI: 10.1071/EA06043

Abstract: Six Australian native herbaceous perennial legumes (Lotus australis, Swainsona colutoides, Swainsona swainsonioides, Cullen tenax, Glycine tabacina and Kennedia prorepens) were assessed in the glasshouse for nutritive value, soluble condensed tannins and production of herbage in response to three cutting treatments (regrowth harvested every 4 and 6 weeks and plants left uncut for 12 weeks). The Mediterranean perennial legumes Medicago sativa and Lotus corniculatus were also included. Dry matter (DM) yield of some native legumes was comparable to L. corniculatus, but M. sativa produced more DM than all species except S. swainsonioides after 12 weeks of regrowth. Dry matter yield of all native legumes decreased with increased cutting frequency, indicating a susceptibility to frequent defoliation. Shoot in vitro dry matter digestibility (DMD) was high ( %) in most native legumes, except G. tabacina (65%) and K. prorepens (55%). Crude protein ranged from 21–28% for all legumes except K. prorepens (12%). More frequent cutting resulted in higher DMD and crude protein in all species, except for the DMD of C. tenax and L. australis, which did not change. Concentrations of soluble condensed tannins were 2–9 g/kg DM in the Lotus spp., 10–18 g/kg DM in K. prorepens and negligible ( g/kg) in the other legumes. Of the native species, C. tenax, S. swainsonioides and L. australis showed the most promise for use as forage plants and further evaluation under field conditions is now warranted.

The agronomic relevance of arbuscular mycorrhizas in the fertility of Australian extensive cropping systems

Publisher: Elsevier BV

Date: 12-2012

DOI: 10.1016/J.AGEE.2012.03.011

Drought resistance and recovery in mature Bituminaria bituminosa var. albomarginata

Publisher: Wiley

Date: 29-10-2014

DOI: 10.1111/AAB.12171

High variation in the percentage of root length colonised by arbuscular mycorrhizal fungi among 139 lines representing the species subterranean clover ( Trifolium subterraneum )

Publisher: Elsevier BV

Date: 02-2016

DOI: 10.1016/J.APSOIL.2015.10.019

Poor regulation of phosphorus uptake and rhizosphere carboxylates in three phosphorus-hyperaccumulating species of Ptilotus

Publisher: Springer Science and Business Media LLC

Date: 29-12-2016

DOI: 10.1007/S11104-015-2784-Y

Novel genes and genetic loci associated with root morphological traits, phosphorus-acquisition efficiency and phosphorus-use efficiency in chickpea

Publisher: Frontiers Media SA

Date: 28-05-2021

DOI: 10.3389/FPLS.2021.636973

Abstract: Chickpea—the second most important grain legume worldwide—is cultivated mainly on marginal soils. Phosphorus (P) deficiency often restricts chickpea yields. Understanding the genetics of traits encoding P-acquisition efficiency and P-use efficiency will help develop strategies to reduce P-fertilizer application. A genome-wide association mapping approach was used to determine loci and genes associated with root architecture, root traits associated with P-acquisition efficiency and P-use efficiency, and any associated proxy traits. Using three statistical models—a generalized linear model (GLM), a mixed linear model (MLM), and a fixed and random model circulating probability unification (FarmCPU) —10, 51, and 40 marker-trait associations (MTAs), respectively were identified. A single nucleotide polymorphism (SNP) locus (Ca1_12310101) on Ca1 associated with three traits, i.e., physiological P-use efficiency, shoot dry weight, and shoot P content was identified. Genes related to shoot P concentration (NAD kinase 2, dynamin-related protein 1C), physiological P-use efficiency (fasciclin-like arabinogalactan protein), specific root length (4-coumarate–CoA ligase 1) and manganese concentration in mature leaves (ABC1 family protein) were identified. The MTAs and novel genes identified in this study can be used to improve P-use efficiency in chickpea.

Increasing mycorrhizal colonisation does not improve growth and nutrition of wheat on Vertosols in south-eastern Australia

Publisher: CSIRO Publishing

Date: 2002

DOI: 10.1071/AR02005

Abstract: Most crops host arbuscular mycorrhizal fungi (AMF). Canola and other brassicas are some of the few exceptions. This study examined AM fungal colonisation, uptake of phosphorus (P) and zinc (Zn), growth, and yield of wheat following brassicas and crops that host AMF in 5 crop-sequence experiments in southern New South Wales and Victoria. All experiments were on alkaline Vertosols, similar to soils in the northern wheatbelt on which low AM fungal colonisation of wheat following canola, or long-fallow, has been reported to induce poor crop growth. Soils with a broad range of extractable P concentrations were chosen. AM fungal colonisation of wheat was generally lower following brassicas than hosts of AMF, although this varied with year and location. The effect on wheat AM fungal colonisation levels did not vary between brassicas with differing levels and types of root glucosinolates. Low AM fungal colonisation did not affect early wheat growth, pre-anthesis P and Zn uptake, or yield. A positive relationship between AM fungal colonisation and grain Zn and P concentrations occurred in one experiment. High levels of colonisation by AMF did not protect crop roots from damage by root pathogens and high levels of pathogen damage made interpretation of results difficult in some instances. As these findings are consistent with results from an experiment on an acidic Kandosol in southern New South Wales, it appears farmers do not need to consider the degree to which wheat will be colonised by AMF when planning crop sequences in south-eastern Australia.

A chronology of subterranean clover burr detachment mechanics and implications for seed harvestability

Publisher: The Royal Society

Date: 11-2021

DOI: 10.1098/RSIF.2021.0625

Abstract: Seed retention has not been evaluated for subterranean clover ( Trifolium subterraneum L.), because its geocarpic seed-bearing burrs are currently harvested by suction systems. Development of improved harvest methods requires knowledge of subterranean clover seed retention characteristics and their changes with plant development. This study evaluates burr attachment and peduncle tensile strength during burr maturity until plant senescence across the three subspecies: subterraneum (cv. Dalkeith), yanninicum (cv. Monti) and brachycalycinum (cv. Mawson). Peduncle tensile strength was greater than burr-to-peduncle attachment strength for each subspecies, with peak mean peduncle strength 30–130% greater than peak mean burr-to-peduncle attachment strength. Both strength measurements decreased significantly (greater than 50% for each subspecies) as the plant senesced, which was associated with reductions in burr moisture content, and burr and peduncle diameters. Microscopy indicated a ductile to brittle transition as peduncles senesced, reducing energy absorption and increasing the likelihood of failure at defects. These results are important for the commercial production of subterranean clover seed and suggest it may be possible to harvest seed before plant senescence with dig-invert machinery, similar to that used for peanut harvesting. However, this approach would require harvesting prior to maximum seed development and the implications for seed viability and yield need to be further evaluated.

The role of root exuded low molecular weight organic anions in facilitating petroleum hydrocarbon degradation: Current knowledge and future directions

Publisher: Elsevier BV

Date: 02-2014

DOI: 10.1016/J.SCITOTENV.2013.11.050

Abstract: Rhizoremediation is a bioremediation technique whereby enhanced microbial degradation of organic contaminants occurs within the plant root zone (rhizosphere). It is considered an effective and affordable 'green technology' for remediating soils contaminated with petroleum hydrocarbons (PHCs). This paper critically reviews the potential role of root exuded compounds in rhizoremediation, with emphasis on commonly exuded low molecular weight aliphatic organic acid anions (carboxylates). The extent to which remediation is achieved shows wide disparity among plant species. Therefore, plant selection is crucial for the advancement and widespread adoption of this technology. Root exudation is speculated to be one of the predominant factors leading to microbial changes in the rhizosphere and thus the potential driver behind enhanced petroleum biodegradation. Carboxylates can form a significant component of the root exudate mixture and are hypothesised to enhance petroleum biodegradation by: i) providing an easily degradable energy source ii) increasing phosphorus supply and/or iii) enhancing the contaminant bioavailability. These differing hypotheses, which are not mutually exclusive, require further investigation to progress our understanding of plant-microbe interactions with the aim to improve plant species selection and the efficacy of rhizoremediation.

Ecological interactions among microbial functional guilds in plant-soil feedback and implications for microbial diversity and ecosystem functions: a mini-review

Publisher: Springer Science and Business Media LLC

Date: 19-05-2022

DOI: 10.1007/S11104-022-05479-1

Response to water‐deficit following waterlogging varies among ecotypes of subterranean clover (Trifolium subterraneum ssp. yanninicum), a waterlogging‐tolerant annual pasture legume

Publisher: Wiley

Date: 03-08-2023

DOI: 10.1111/AAB.12856

Abstract: The pasture legume Trifolium subterraneum ssp. yanninicum L. is waterlogging tolerant, but water‐deficit (WD) susceptible. The interactive effect of waterlogged (WL) and WD (soil moisture fluctuation [SMF]) results in a severe stress impact. We studied three erse ecotypes to identify traits associated with adaptation to SMF. Ecotypes were established in a glasshouse with two treatments imposed at 21 days: well‐watered (WW–WW 80% field capacity [FC]) and WL to WD (WL–WD). For WL–WD, pots were WL for 28 days (Harvest I), and then transitioned to WD (drained to 40% FC) and maintained for 10 days (Harvest II). For shoot relative growth rates (RGR) at Harvest I, WL had relatively little impact, although there was a greater reduction for Ecotype A (80% of WW) than Ecotypes B (92%) and C (87%). However, between Harvests I and II, the impact of WL–WD varied among ecotypes with Ecotype A being less affected (75% of WW–WW) than Ecotypes B (57%) and C (63%). For root RGR at Harvest I, WL resulted in a greater reduction for Ecotype A (52% of WW) than Ecotypes B (77%) and C (74%), while for WL–WD between Harvests I and II, Ecotype A showed a large increase (117% of WW–WW) compared to Ecotypes B (95%) and C (87%). In conclusion, the response to WD following WL varied among ecotypes, which demonstrates contrasting adaptation responses to SMF unrelated to WL tolerance. High yield under WL together with capacity for rapid growth post‐WL in a drying soil profile could enhance adaptation to SMF.

Drought resistance at the seedling stage in the promising fodder plant tedera (Bituminaria bituminosa var. albomarginata)

Publisher: CSIRO Publishing

Date: 2012

DOI: 10.1071/CP12216

Abstract: The perennial legume Bituminaria bituminosa (L.) C.H. Stirt. var. albomarginata (tedera) has been identified as a promising fodder plant for the southern Australian wheatbelt, but little is known about its drought resistance as a seedling. This study was conducted to (i) examine physiological and morphological responses to water stress of seedlings of tedera, in comparison with lucerne (Medicago sativa L.), biserrula (Biserrula pelecinus L.) and Afghan melon (Citrullus lanatus Thunb.), and (ii) investigate drought adaptation mechanisms of tedera seedlings. Seedlings were grown in a reconstructed field soil profile in pots in a glasshouse. By 25 days after sowing (DAS), plants of all species in the drought-stressed (DS) treatment had experienced water stress, with an average leaf relative water content (RWC) of 66% in DS compared with 79% in well-watered (WW) plants. Tedera, biserrula and Afghan melon maintained a higher RWC than lucerne. At 25 DAS, reductions in shoot dry matter in the DS treatment differed between species: 52% for Afghan melon, 36% for biserrula, 27% for lucerne, and no significant reduction for tedera. Paraheliotropic leaf angles of biserrula, lucerne and tedera were all higher in the DS treatment than in the WW treatment at 25, 32 and 52 DAS. This study revealed significant differences in rooting depth and stomatal conductance between the three legume species when under water stress, with tedera being the most drought-resistant. Traits that may allow tedera to survive a dry period following opening rains include vigorous seedling growth, early taproot elongation, effective stomatal control and paraheliotropic leaf movements.

Phosphorus acquisition and utilisation in crop legumes under global change

Publisher: Elsevier BV

Date: 10-2018

DOI: 10.1016/J.PBI.2018.05.012

Abstract: Improving phosphorus (P)-use efficiency in legumes is a worldwide challenge in the face of an increasing world population, dwindling global rock phosphate reserves, the relatively high P demand of legumes and global change. This review focuses on P acquisition of crop legumes in response to climate change. We advocate further studies on: firstly, the response of carboxylate exudation, mycorrhizas and root morphology to climate change and their role in P acquisition as dependent on edaphic factors secondly, developing intercropping systems with a combination of a legume and another crop species to enhance P acquisition and thirdly, the impact of the interactions of the major climate change factors on P acquisition in the field.

Making science more effective for agriculture

Publisher: Elsevier

Date: 2020

DOI: 10.1016/BS.AGRON.2020.05.003

Taxonomic and pathogenic characteristics of a new species Aphanomyces trifolii causing root rot of subterranean clover (Trifolium subterraneum) in Western Australia

Publisher: CSIRO Publishing

Date: 2010

DOI: 10.1071/CP10040

Abstract: Subterranean clover (Trifolium subterraneum) is grown extensively as a pasture legume in agronomic regions with Mediterranean-type climates in parts of Africa, Asia, Australia, Europe, North America and South America. Root diseases of subterranean clover, especially those caused by oomycete pathogens including Aphanomyces, Phytophthora and Pythium, greatly reduce productivity by significantly decreasing germination, seedling establishment, plant survival and seed set. For this reason, experiments were conducted to determine the species of Aphanomyces causing root disease on subterranean clover in the high-rainfall areas of south-west Western Australia. The effects of flooding, temperature and inoculum concentration on the development of root disease on subterranean clover caused by this Aphanomyces sp. were also investigated as was its host range. Morphological and molecular characteristics were used to identify the pathogen as a new species Aphanomyces trifolii sp. nov. (O’Rourke et al.), which forms a distinct clade with its nearest relative being A. cladogamus. A. trifolii caused significant lateral root pruning as well as hypocotyl collapse and tap root disease of subterranean clover. The level of disease was greater in treatments where soil was flooded for 24 h rather than for 6 h or in unflooded treatments. The pathogen caused more disease at 18/13oC than at lower (10/5oC) or higher (25/20oC) temperatures. The pathogen caused more disease at 1% inoculum than at 0.5 or 0.2% (% inoculum : dry weight of soil). In greenhouse trials, A. trifolii also caused root disease on annual medic (M. polymorpha and M. truncatula), dwarf beans (Phaseolus vulgaris) and tomatoes (Solanum lycopersicum). However, the pathogen did not cause disease on peas (Pisum sativum), chickpea (Cicer arietinum), wheat (Triticum aestivum), annual ryegrass (Lolium rigidium) or capsicum (Capsicum annuum). A. trifolii is a serious pathogen in the high-rainfall areas of south-west Western Australia and is likely a significant cause of root disease and subsequent decline in subterranean clover pastures across southern Australia.

The potential of herbaceous native Australian legumes as grain crops: a review

Publisher: Cambridge University Press (CUP)

Date: 18-08-2011

DOI: 10.1017/S1742170510000347

Abstract: Many agricultural systems around the world are challenged by declining soil resources, a dry climate and increases in input costs. The cultivation of plants that are better adapted than current crop species to nutrient poor soils, a dry climate and low-input agricultural systems would aid the continued profitability and environmental sustainability of agricultural systems. This paper examines herbaceous native Australian legumes for their capacity to be developed as grain crops adapted to dry environments. The 14 genera that contain herbaceous species are Canavalia, Crotalaria, Cullen, Desmodium, Glycine, Glycyrrhiza, Hardenbergia, Indigofera, Kennedia, Lotus, Rhynchosia, Swainsona, Trigonella and Vigna . A number of these genera (e.g., Glycine, Crotalaria, Trigonella and Vigna ) include already cultivated exotic grain legumes. Species were evaluated based on the extent to which their natural distribution corresponded to arid and semi-arid climatic regions, as well as the existing information on traits related to harvestability (uniformity of ripening, propensity to retain pod, pod shattering and growth habit), grain qualities (seed size, chemistry, color and the absence of toxins) and fecundity. Published data on seed yield were rare, and for many other traits information was limited. The Australian species of Vigna , Canavalia and Desmodium mainly have tropical distributions and were considered poorly suited for semi-arid temperate cropping systems. Of the remaining genera Glycyrrhiza and Crotalaria species showed many suitable traits, including an erect growth habit, a low propensity to shatter, flowers and fruits borne at the end of branches and moderate to large seeds (5 and 38 mg, respectively). The species for which sufficient information was available that were considered highest priority for further investigation were Glycine canescens, Cullen tenax, Swainsona canescens, Swainsona colutoides, Trigonella suavissima, Kennedia prorepens, Glycyrrhiza acanthocarpa, Crotalaria cunninghamii and Rhynchosia minima.

Soil types select for plants with matching nutrient‐acquisition and ‐use traits in hyperdiverse and severely nutrient‐impoverished campos rupestres and cerrado in Central Brazil

Publisher: Wiley

Date: 31-12-2018

DOI: 10.1111/1365-2745.13111

Advances in understanding plant root uptake of phosphorus

Publisher: Burleigh Dodds Science Publishing

Date: 19-01-2021

DOI: 10.19103/AS.2020.0075.16

Abstract: At a global scale, phosphorus (P) deficiency comprises a large area of cropland, while P has also been used in excess of crop requirements in many other regions. Improved crop P-acquisition efficiency would allow lower target critical soil P values and provide savings in P-fertiliser use. At the same time, it would reduce P lost through erosion, leaching and/or soil sorption. This chapter summarises the progress in research on root traits associated with P acquisition, including root morphology, architecture, biochemistry, colonisation by arbuscular mycorrhizal fungi, and fine root endophytes, and the trade-offs among all these traits. Farming-management practices to improve P acquisition under current intensive agricultural systems are also discussed. The chapter summarises breeding progress in improving P-acquisition efficiency. In the face of soil P deficiency or legacy P globally, the chapter suggests future directions to improve P acquisition in five key areas.

A century of subclover: Lessons for sustainable intensification from a historical review of innovations in subterranean clover seed production

Publisher: Elsevier

Date: 2022

DOI: 10.1016/BS.AGRON.2021.08.003

From controlled environments to field simulations: Developing a growth model for the novel perennial pasture legume Cullen australasicum

Publisher: Elsevier BV

Date: 15-09-2010

DOI: 10.1016/J.AGRFORMET.2010.06.008

Magnitude and mechanisms of persistent crop sequence effects on wheat

Publisher: Elsevier BV

Date: 08-2014

DOI: 10.1016/J.FCR.2014.05.005

Putting the P in Ptilotus: a phosphorus-accumulating herb native to Australia

Publisher: Oxford University Press (OUP)

Date: 12-02-2009

DOI: 10.1093/AOB/MCP021

Damage to roots of Trifolium subterraneum L. (subterranean clover), failure of seedlings to establish and the presence of root pathogens during autumn-winter

Publisher: Wiley

Date: 02-10-2011

DOI: 10.1111/J.1365-2494.2011.00822.X

Field benchmarking of the critical external phosphorus requirements of pasture legumes for southern Australia

Publisher: CSIRO Publishing

Date: 2019

DOI: 10.1071/CP19014

Abstract: In recent decades several pasture legumes have been available in southern Australia as potential alternatives to the most widely used annual pasture legume Trifolium subterraneum. Little is known about their soil phosphorus (P) requirements, but controlled environment experiments indicate that at least some may differ in their P fertiliser requirements. In this study, pasture legume varieties, including T. subterraneum as the reference species, were grown at up to four sites in any one year over a 3-year period (in total, seven site × year experiments) to measure herbage growth responses in spring to increased soil P availability. A critical soil test P concentration (corresponding to 95% maximum yield) was estimated for 15 legumes and two pasture grasses. The critical soil P requirements of most of the legumes did not differ consistently from that of T. subterraneum, indicating their soil fertility management should follow the current soil test P guidelines for temperate Australian pastures. However, the critical P requirement of Medicago sativa was higher than that of T. subterraneum, but remains ill-defined because extractable soil P concentrations in these experiments were often not high enough to permit a critical P estimate. Three forage crop legumes (Trifolium incarnatum, Trifolium purpureum, Trifolium vesiculosum) and two pasture legumes (Ornithopus compressus, Ornithopus sativus) had lower critical soil test P concentrations. It may be feasible to manage pastures based on these species to a lower soil test P benchmark without compromising yield.

Defining the waterlogging tolerance of Ornithopus spp. for the temperate pasture zone of southern Australia

Publisher: CSIRO Publishing

Date: 2020

DOI: 10.1071/CP19491

Abstract: Increasing the area sown to Ornithopus spp. (serradella) can reduce overall fertiliser requirements in Australian permanent pastures owing to their greater nutrient-acquisition efficiency than that of more widely used pasture legumes such as Trifolium spp. However, uncertainty regarding waterlogging tolerance of Ornithopus spp. may restrict their adoption in the high-rainfall zone of southern Australia. The waterlogging tolerance of cultivars and accessions of three species of Ornithopus (O. compressus, O. sativus and O. pinnatus) was determined by comparing root and shoot growth of plants in deoxygenated, stagnant agar nutrient solution (simulated waterlogging) with growth in aerated nutrient solution. The responses were benchmarked against the known waterlogging-tolerant pasture legume Trifolium michelianum. All Ornithopus cultivars were highly impacted by the deoxygenated stagnant treatment, including those of the anecdotally waterlogging-tolerant O. pinnatus. The 14-day stagnant treatment reduced root dry mass by 32–62% and relative growth rate (RGR) of roots by 36–73%. At the same time, root porosity increased from 1.4% to 8.8%. Following a 14-day recovery period, during which plants were returned to aerated nutrient solution, Ornithopus spp. failed to increase their shoot RGR (particularly for O. sativus cultivars) however, root RGR returned to that of the aerated controls. The stagnant conditions inhibited transport of potassium (K+) to the shoots in all species, as evidenced by lower shoot tissue K+ concentrations, with O. compressus and O. sativus most adversely affected (45% and 48% of the tissue concentration of aerated control plants). We conclude that the suggested area for Ornithopus spp. adaptation should not preclude areas of high rainfall because they have root adaptations that would assist them in coping with transient water excess however, soil types and surface profiles conducive to long-term waterlogging should be avoided to negate significant productivity losses.

Grain mineral concentrations and yield of wheat grown under organic and conventional management

Publisher: Wiley

Date: 12-01-2004

DOI: 10.1002/JSFA.1634

Phosphorus fractions in leaves

Publisher: Wiley

Date: 02-12-2023

DOI: 10.1111/NPH.18588

Abstract: Leaf phosphorus (P) comprises four major fractions: inorganic phosphate (P i ), nucleic acids, phospholipids, P‐containing metabolites and a residual fraction. In this review paper, we investigated whether allocation of P fractions varies among groups of terrestrial vascular plants, and is indicative of a species' strategy to use P efficiently. We found that as leaf total P concentration increases, the P i fraction increases the most, without a plateau, while other fractions plateau. Variability of the concentrations of leaf P fractions is greatest among families species(family) regions plant life forms. The percentage of total P allocated to nucleic acid‐P (20–35%) and lipid‐P (14–34%) varies less among families/species. High photosynthetic P‐use efficiency is associated with low concentrations of all P fractions, and preferential allocation of P to metabolite‐P and mesophyll cells. Sequential resorption of P from senescing leaves starts with P i , followed by metabolite‐P, and then other organic P fractions. Allocation of P to leaf P fractions varies with season. Leaf phytate concentrations vary considerably among species, associated with variation in photosynthesis and defence. Plasticity of P allocation to its fractions is important for acclimation to low soil P availability, and species‐specific P allocation is needed for co‐occurrence with other species.

Fine endophytes (Glomus tenue) are related to Mucoromycotina, not Glomeromycota

Publisher: Wiley

Date: 21-10-2016

DOI: 10.1111/NPH.14268

Large variation in waterlogging tolerance and recovery among the three subspecies of Trifolium subterranean L. is related to root and shoot responses

Publisher: Springer Science and Business Media LLC

Date: 29-04-2021

DOI: 10.1007/S11104-021-04959-0

Root hair morphology and mycorrhizal colonisation of pasture species in response to phosphorus and nitrogen nutrition

Publisher: CSIRO Publishing

Date: 2010

DOI: 10.1071/CP09217

Abstract: Root hairs and arbuscular mycorrhizal fungi (AMF) increase the absorptive surface area of a root and the volume of soil explored and as such are important for nutrient acquisition in infertile soil. Root hair morphology and colonisation by AMF were compared for 10 temperate pasture species, and responses to N and P deficiency characterised. Vulpia spp., Holcus lanatus, and Lolium rigidum had the longest root hairs (range 1.02–2.36 mm) while Trifolium subterraneum had the shortest (~0.27 mm). In contrast, T. subterraneum had a much higher density of root hairs than any of the other species. In response to P deficiency, the length and density of root hairs generally increased in response to N deficiency, both increases and decreases in the length and density of root hairs were observed. The annual dicotyledons T. subterraneum and Arctotheca calendula had much higher mycorrhizal colonisation on roots grown at low P availability than the grasses. Root colonisation decreased with increasing P availability in all species. A yield advantage from mycorrhizal colonisation was demonstrated only for T. subterraneum when P was deficient. The potential root cylinder volume of each species was calculated as an index of the ability of the species to explore soil. Although all plant species were colonised by AMF, a positive linear relationship was observed between relative P uptake rate from the soil and the rate at which potential root cylinder volumes were developed by most species. Development of potential root cylinder volume also largely explained the critical external P requirements of most species. No such relationships were observed for N. It was concluded that knowledge of root length and the length of root hairs grown in nutrient-poor conditions may be used to predict the potential of many plant species to acquire P, and also their critical external P requirement for maximum growth. However, the study also highlighted some exceptional species.

CO2 concentration and water availability alter the organic acid composition of root exudates in native Australian species

Publisher: Springer Science and Business Media LLC

Date: 13-01-2023

DOI: 10.1007/S11104-022-05845-Z

Abstract: Root exudation of organic acids (OAs) facilitates plant P uptake from soil, playing a key role in rhizosphere nutrient availability. However, OA exudation responses to CO 2 concentrations and water availability remain largely untested. We examined the effects of CO 2 and water on OA exudates in three Australian woodland species: Eucalyptus tereticornis , Hakea sericea and Microlaena stipoides . Seedlings were grown in a glasshouse in low P soil, exposed to CO 2 (400 ppm [aCO 2 ] or 540 ppm [eCO 2 ]) and water treatments (100% water holding capacity [high-watered] or 25–50% water holding capacity [low-watered]). After six weeks, we collected OAs from rhizosphere soil ( OA rhizo ) and trap solutions in which washed roots were immersed ( OA exuded ). For E. tereticornis , the treatments changed OA rhizo composition, driven by increased malic acid in plants exposed to eCO 2 and increased oxalic acid in low-watered plants. For H. sericea , low-watered plants had higher OA exuded per plant (+ 116%) and lower OA rhizo per unit root mass (–77%) associated with larger root mass but fewer cluster roots. For M. stipoides , eCO 2 increased OA exuded per plant (+ 107%) and per unit root mass (+ 160%), while low-watered plants had higher citric and lower malic acids for OA rhizo and OA exuded : changes in OA amounts and composition driven by malic acid were positively associated with soil P availability under eCO 2. We conclude that eCO 2 and altered water availability shifted OAs in root exudates, modifying plant–soil interactions and the associated carbon and nutrient economy.

Variation in seedling growth of 11 perennial legumes in response to phosphorus supply

Publisher: Springer Science and Business Media LLC

Date: 04-07-2010

DOI: 10.1007/S11104-009-0088-9

Phenotypic variation for productivity and drought tolerance is widespread in germplasm collections of Australian Cullen species

Publisher: CSIRO Publishing

Date: 2012

DOI: 10.1071/CP11338

Abstract: Cullen australasicum is a legume species from Australia that holds promise for development as a drought-tolerant perennial pasture species, yet only a few accessions have been evaluated for agronomic traits. Several Cullen species aside from C. australasicum may also have potential for use as perennial pastures. We compared the field survival and aboveground biomass production of 100 germplasm accessions from 9 Cullen species, 2 lucerne (Medicago sativa) cultivars and 2 perennial Lotus species over 18 months in a low-rainfall region of the wheatbelt of Western Australia. Nutritive value of selected Cullen accessions was also compared with lucerne and L. australis. Several accessions of C. australasicum demonstrated good survival, productivity and nutritional value, and some accessions of C. discolor, C. lachnostachys, C. pallidum and C. pustulatum also showed promise in some or all of these traits. Significant phenotypic variation was seen among accessions of C. australasicum, C. pallidum, C. cinereum and C. tenax for some agronomic traits. We discuss the implications of this variation for further experiments or development of Cullen species. While survival and productivity of many Cullen accessions was similar to lucerne, only a few C. australasicum accessions were more productive than lucerne. We conclude that C. australasicum is currently the best prospect among Cullen species for cultivar development as a perennial pasture legume, and our analysis has highlighted accessions of particular interest. In addition, further work on C. discolor, C. lachnostachys, C. pallidum and C. pustulatum may also, in the longer term, provide useful pasture species.

Mechanisms for tolerance of very high tissue phosphorus concentrations in Ptilotus polystachyus

Publisher: Wiley

Date: 11-11-2014

DOI: 10.1111/PCE.12450

Abstract: Study of plants with unusual phosphorus (P) physiology may assist development of more P-efficient crops. Ptilotus polystachyus grows well at high P supply, when shoot P concentrations ([P]) may exceed 40 mg P g(-1) dry matter (DM). We explored the P physiology of P. polystachyus seedlings grown in nutrient solution with 0-5 mM P. In addition, young leaves and roots of soil-grown plants were used for cryo-scanning electron microscopy and X-ray microanalysis. No P-toxicity symptoms were observed, even at 5 mM P in solution. Shoot DM was similar at 0.1 and 1.0 mM P in solution, but was ∼14% lower at 2 and 5 mM P. At 1 mM P, [P] was 36, 18, 14 and 11 mg P g(-1) DM in mature leaves, young leaves, stems and roots, respectively. Leaf potassium, calcium and magnesium concentrations increased with increasing P supply. Leaf epidermal and palisade mesophyll cells had similar [P]. The root epidermis and most cortical cells had senesced, even in young roots. We conclude that preferential accumulation of P in mature leaves, accumulation of balancing cations and uniform distribution of P across leaf cell types allow P. polystachyus to tolerate very high leaf [P].

The carboxylate‐releasing phosphorus‐mobilizing strategy can be proxied by foliar manganese concentration in a large set of chickpea germplasm under low phosphorus supply

Publisher: Wiley

Date: 14-05-2018

DOI: 10.1111/NPH.15200

Abstract: Root foraging and root physiology such as exudation of carboxylates into the rhizosphere are important strategies for plant phosphorus (P) acquisition. We used 100 chickpea (Cicer arietinum) genotypes with erse genetic backgrounds to study the relative roles of root morphology and physiology in P acquisition. Plants were grown in pots in a low-P sterilized river sand supplied with 10 μg P g

Variation in morphological and physiological root traits and organic acid exudation of three sweet potato (Ipomoea batatas) cultivars under seven phosphorus levels

Publisher: Elsevier BV

Date: 10-2019

DOI: 10.1016/J.SCIENTA.2019.108572

Establishment, survival, and herbage production of novel, summer-active perennial pasture legumes in the low-rainfall cropping zone of Western Australia as affected by plant density and cutting freque

Publisher: CSIRO Publishing

Date: 2013

DOI: 10.1071/CP12398

Abstract: Herbaceous perennial legumes that can provide forage in the summer–autumn dry period are urgently required in Mediterranean climates to complement annual pastures and the perennial legume lucerne (Medicago sativa). This study evaluated the establishment, survival, and herbage production of tedera (Bituminaria bituminosa var. albomarginata) and Cullen spp. native to Australia. Two experiments were replicated at Buntine (warmer site) and Newdegate (cooler site) in the low-rainfall cropping zone ( mm average annual rainfall) of Western Australia from June 2008 to September 2010. In the first experiment, established by transplanting seedlings, survival and herbage production of two accessions each of B. bituminosa and C. australasicum were studied under densities of 1, 2, 4, 8, and 16 plants/m2 with 0, 1, 2, or 3 cuts in summer–autumn in addition to a winter–spring cut. In the second experiment, established from seed, emergence and survival of several accessions of B. bituminosa, C. australasicum, and M. sativa were studied, along with C. pallidum and C. cinereum. In the first experiment, B. bituminosa survived better than C. australasicum (70–80% v. 18–45%), especially at Buntine, but there was little impact of density or cutting frequency on survival. Plant death was highest during summer. Shoot dry weight (DW) accumulation varied greatly with site, year, and plant density. When rainfall was close to average, shoot DW was greater at Newdegate (B. bituminosa ≤7.4 t/ha, C. australasicum ≤4.5 t/ha) than at Buntine (≤2.3 t/ha), and both species produced much of their shoot DW in summer–autumn (e.g. 6 t/ha for B. bituminosa and 3 t/ha for C. australasicum at Newdegate). An early-summer cut reduced the DW that could be harvested later in summer–autumn. In the second experiment, emergence of B. bituminosa was either similar to, or higher than, emergence of the other species, being 43% at Buntine and 44% at Newdegate. Survival of B. bituminosa, compared with M. sativa, was similar at Buntine (13%) and slightly lower at Newdegate (14%). Emergence and survival of Cullen spp. varied among species and accessions, with survival of the best performing accession of C. australasicum (SA4966) similar to that of B. bituminosa and M. sativa at both sites. We conclude that B. bituminosa shows promise as a perennial summer forage for low-rainfall zones, with a density of 8–16 plants/m2 and cutting frequency of 3 cuts/year (i.e. cut twice in summer–autumn), while C. australasicum and C. pallidum warrant further study.

Farmer-driven innovation: lessons from a case study of subterranean clover seed production

Publisher: Pluto Journals

Date: 2022

DOI: 10.13169/PROMETHEUS.37.4.0353

Abstract: Farmers are often overlooked and undervalued as sources of innovation, but can be powerful drivers of ingenuity and development. We evaluate historical developments in the Australian subterranean clover seed-production industry as a case study of farmer-driven innovation. Subterranean clover seed machinery patents (75% of which were patented by farmers) are analysed using conventional innovation frameworks, such as the theory of inventive problem solving (TRIZ), to extract lessons for supporting farmer-driven innovation. The small scale of this industry, compared with mainstream cereal-cropping industries and the isolation of farmers, provides analogous lessons for agriculture in developing countries. Economic drivers are important in enabling farmer innovation and the value proposition for developing new inventions must be clear to justify the time and expense. Farmers are different from firms and their on-farm knowledge and experience can form an essential part of innovation. Drivers of innovation also differ, with farmers less likely to attempt to commercialize inventions. Farmers can also be hesitant to share their inventions, instead holding them as trade secrets in competitive industries. Support and collaboration are needed from government and researchers to assist in commercialization or dissemination of useful innovations and to prevent knowledge from being confined to a localized farmer or region. Advances in agriculture require farmer input in research and development, but the benefits will be greater if farmers are enabled to be drivers of innovation.

Plant Responses to Limited Moisture and Phosphorus Availability

Publisher: Elsevier

Date: 2014

DOI: 10.1016/B978-0-12-800138-7.00004-8

Leaf formononetin content of Trifolium subterraneum increases in response to waterlogging but its proportion of total isoflavones is little changed

Publisher: CSIRO Publishing

Date: 05-05-2023

DOI: 10.1071/FP22151

Abstract: The isoflavone formononetin (F) impacts livestock fertility and cultivars of the pasture legume Trifolium subterraneum L. (subclover) have been selected for F levels ≤0.2% of leaf dry weight. However, the impact of waterlogging (WL) on isoflavones is little studied. We investigated the response of isoflavones, biochanin A (BA), genistein (G) and F, to WL for: (1) Yarloop (high F) and eight low F cultivars each from subspecies subterraneum, brachycalycinum and yanninicum (Experiment 1) and (2) four cultivars and 12 ecotypes of ssp. yanninicum (Experiment 2). WL impacted F: estimated means increased from 0.19% (control) to 0.31% (WL) in Experiment 1 and from 0.61% to 0.97% in Experiment 2. Isoflavones under WL were highly heritable, particularly F (H2 = 95%). The proportions of BA, G and F were little changed by WL, with strong positive correlations between free-drained and waterlogged treatments. Isoflavone contents were not related to WL tolerance, as assessed by shoot relative growth rate. In conclusion, isoflavones varied among genotypes and increased with WL, but the proportion of in idual isoflavones in each genotype was stable. High F under WL was unrelated with genotype tolerance to WL. Instead, it was a consequence of inherently high F for that particular genotype.

Root morphology and its contribution to a large root system for phosphorus uptake by Rytidosperma species (wallaby grass)

Publisher: Springer Science and Business Media LLC

Date: 27-06-2016

DOI: 10.1007/S11104-016-2933-Y

Research must use a systems agronomy approach if management of the arbuscular mycorrhizal symbiosis is to contribute to sustainable intensification

Publisher: Wiley

Date: 18-01-2019

DOI: 10.1111/NPH.15600

Oxygen loss from seagrass roots coincides with colonisation of sulphide-oxidising cable bacteria and reduces sulphide stress

Publisher: Springer Science and Business Media LLC

Date: 23-10-2019

DOI: 10.1038/S41396-018-0308-5

Colonizing tropical seagrasses increase root exudation under fluctuating and continuous low light

Publisher: Wiley

Date: 16-11-2018

DOI: 10.1002/LNO.10746

Moderating mycorrhizas: arbuscular mycorrhizas modify rhizosphere chemistry and maintain plant phosphorus status within narrow boundaries

Publisher: Wiley

Date: 25-10-2013

DOI: 10.1111/PCE.12207

Abstract: Pastures often experience a pulse of phosphorus (P) when fertilized. We examined the role of arbuscular mycorrhizal fungi (AMF) in the uptake of P from a pulse. Five legumes (Kennedia prostrata, Cullen australasicum, Bituminaria bituminosa, Medicago sativa and Trifolium subterraneum) were grown in a moderate P, sterilized field soil, either with (+AMF) or without (-AMF) addition of unsterilized field soil. After 9-10 weeks, half the pots received 15 mg P kg(-1) of soil. One week later, we measured: shoot and root dry weights percentage of root length colonized by AMF plant P, nitrogen and manganese (Mn) concentrations and rhizosphere carboxylates, pH and plant-available P. The P pulse raised root P concentration by a similar amount in uncolonized and colonized plants, but shoot P concentration increased by 143% in uncolonized plants and 53% in colonized plants. Inoculation with AMF decreased the amount of rhizosphere carboxylates by 52%, raised rhizosphere pH by ∼0.2-0.7 pH units and lowered shoot Mn concentration by 38%. We conclude that AMF are not simply a means for plants to enhance P uptake when P is limiting, but also act to maintain shoot P within narrow boundaries and can affect nutrient uptake through their influence on rhizosphere chemistry.

Prospects for three Dorycnium species as forage plants in agricultural systems: a review of their agronomic characteristics

Publisher: CSIRO Publishing

Date: 2008

DOI: 10.1071/EA07109

Abstract: Perennial legumes in the Dorycnium genus may have potential as forage plants that could reduce the seasonality of feed production and improve the sustainability of agricultural systems. However, Dorycnium species are not currently used commercially and little is known about their agronomic characteristics. This review covers the current knowledge on Dorycnium distribution, taxonomy and the agronomic performance of Dorycnium hirsutum, Dorycnium rectum and Dorycnium pentaphyllum, including adaptation, establishment, biomass production, water use, grazing management and nitrogen fixation, along with considerations for animal production. Dorycnium originate from temperate Europe and the Mediterranean basin and may be suitable for other regions with similar climatic conditions. Little data exist on the climatic and edaphic conditions to which Dorycnium species are best adapted. Current evidence suggests that D. hirsutum is widely adapted and might be suitable as a forage plant for acid soils in drier and frost-prone agricultural regions. D. hirsutum also persists well in low rainfall environments (down to 300 mm mean annual rainfall), can produce up to 21 t dry matter(DM)/ha in its first 3 years and, by utilising extra water compared with annual pastures, can reduce water leakage below the root zone, thereby slowing development of dryland salinity. The use of D. rectum would be limited to high rainfall or water-accumulating sites. D. pentaphyllum is a erse species, yet available material appears to be less productive but has better forage quality than D. hirsutum. Currently, establishment reliability and/or forage digestibility are major limitations of the tested Dorycnium species that restrict their potential role and challenge the feasibility of their future use. Breeding may overcome or minimise these limitations and improved agronomic management might also enhance their usefulness. However, current collected genetic resources of Dorycnium are very limited and targeted collections would be needed to yield better adapted germplasm. Breeding to reduce the high levels of condensed tannins ( % of DM) to moderate concentrations in Dorycnium might improve forage digestibility and could have positive implications for animal performance and health. Despite the poor digestibility of some Dorycnium species ( % DM digestibility), these plants may still play a significant role as drought forage to provide feed when other forage sources are in limited supply. Further research is required to quantify the potential of Dorycnium species for commercial release and to determine how these plants should be best managed and integrated into livestock and mixed cropping systems.

Leaf transpiration plays a role in phosphorus acquisition among a large set of chickpea genotypes

Publisher: Wiley

Date: 23-03-2018

DOI: 10.1111/PCE.13139

Abstract: Low availability of inorganic phosphorus (P) is considered a major constraint for crop productivity worldwide. A unique set of 266 chickpea (Cicer arietinum L.) genotypes, originating from 29 countries and with erse genetic background, were used to study P-use efficiency. Plants were grown in pots containing sterilized river sand supplied with P at a rate of 10 μg P g

Closing the circle for urban food waste anaerobic digestion

Publisher: Elsevier BV

Date: 05-2022

DOI: 10.1016/J.JCLEPRO.2022.131071

Globular structures in roots accumulate phosphorus to extremely high concentrations following phosphorus addition

Publisher: Wiley

Date: 26-03-2019

DOI: 10.1111/PCE.13531

Abstract: Crops with improved uptake of fertilizer phosphorus (P) would reduce P losses and confer environmental benefits. We examined how P-sufficient 6-week-old soil-grown Trifolium subterraneum plants, and 2-week-old seedlings in solution culture, accumulated P in roots after inorganic P (Pi) addition. In contrast to our expectation that vacuoles would accumulate excess P, after 7 days, X-ray microanalysis showed that vacuolar [P] remained low (<12 mmol kg

Growth and root dry matter allocation by pasture legumes and a grass with contrasting external critical phosphorus requirements

Publisher: Springer Science and Business Media LLC

Date: 02-02-2016

DOI: 10.1007/S11104-016-2808-2

The response of fine root endophyte (Glomus tenue) to waterlogging is dependent on host plant species and soil type

Publisher: Springer Science and Business Media LLC

Date: 27-01-2016

DOI: 10.1007/S11104-016-2804-6

Mulling over the mulla mullas: revisiting phosphorus hyperaccumulation in the Australian plant genus Ptilotus (Amaranthaceae)

Publisher: CSIRO Publishing

Date: 2020

DOI: 10.1071/BT19188

Abstract: Species in the Australian genus Ptilotus (Amaranthaceae) grow well in soils with both very low and very high phosphorus (P) availability in the latter they hyperaccumulate P. However, it is not known whether this trait is common within Ptilotus, whether it is shared with other genera in the family, or whether it correlates with the wide array of morphologies and ecologies within Ptilotus. We therefore assessed P hyperaccumulation across the morphological, ecological and phylogenetic ersity of Ptilotus. Experiment 1 tested the response of 11 species to added P (0, 50 and 100 mg kg–1), including six species of Ptilotus and the Australian amaranth Gomphrena canescens R.Br. Experiment 2 tested the response of five species – three Ptilotus spp., G. canescens and Kennedia prostrata R.Br. – to added P (5 and 150 mg kg–1) and two pre-harvest P-pulse treatments (5 and 50 mg kg–1). Ptilotus species hyperaccumulated P when grown in high-P soil, but curtailed uptake from a pulse. All Ptilotus species preferentially allocated P to leaves (reaching 73 mg g–1) without development of P toxicity symptoms. Gomphrena canescens and K. prostrata preferentially allocated P to stems and roots, respectively, and suffered P toxicity. The lack of tolerance to high [P] in G. canescens suggests that the likely widespread, or universal, mechanisms for tolerance of high P by Ptilotus are not shared by amaranths. Further research will determine the mechanisms underlying the unusual P physiology of Ptilotus.

First Cryo-Scanning Electron Microscopy Images and X-Ray Microanalyses of Mucoromycotinian Fine Root Endophytes in Vascular Plants

Publisher: Frontiers Media SA

Date: 03-09-2020

DOI: 10.3389/FMICB.2020.02018

Growth, carboxylate exudates and nutrient dynamics in three herbaceous perennial plant species under low, moderate and high phosphorus supply

Publisher: Springer Science and Business Media LLC

Date: 10-06-2012

DOI: 10.1007/S11104-012-1311-7

The where, when and what of phosphorus fertilisation for seedling establishment in a biodiverse jarrah forest restoration after bauxite mining in Western Australia

Publisher: Elsevier BV

Date: 06-2020

DOI: 10.1016/J.ECOLENG.2020.105907

Comparison of novel and standard methods for analysing patterns of plant death in designed field experiments

Publisher: Cambridge University Press (CUP)

Date: 04-07-2011

DOI: 10.1017/S0021859611000566

Abstract: The present paper compares standard and novel methods for analysing aggregated patterns of plant death in designed field experiments these methods include binomial (BN), beta-binomial (BBN), logistic-normal-binomial (LNB), BN models with random blocks, BN models with smooth-scale spatial components and principal coordinates of neighbour matrices (PCNM). PCNM is a relatively new technique used in ecology to determine how much observed variability can be explained by spatial and environmental variables, and has not yet been applied to agricultural studies. The survival data of two pasture species, collected from a designed field experiment that was replicated at multiple locations, were used. First, the occurrence of overdispersion was tested using the BN and BBN distributions. Goodness-of-fit tests proved that the BBN model provided a better description (better fit) of the observed data in some cases than did the BN distribution, indicating overdispersion was present. When overdispersion was not present, the BN distribution was adequate to describe the data, and the use of the BBN distribution was superfluous. It is then shown that the PCNM approach, the BN model with smooth-scale spatial components and the LNB model were able to account for some of the variation as spatial variability, thus reducing the species effect compared with that explained under the standard BN model. The amount of variation among species according to the BN model and the BN model with random blocks was similar. Therefore, it is argued that the novel PCNM approach warrants further testing when exploring the spatial variability in designed experiments in agriculture and using LNB, PCNM and BN with smooth-scale spatial components may provide better predictions of species effects than do other, more conventional, approaches.

Soil phosphorus supply affects nodulation and N:P ratio in 11 perennial legume seedlings

Publisher: CSIRO Publishing

Date: 2011

DOI: 10.1071/CP11229

Abstract: Developing new perennial pasture legumes for low-P soils is a priority for Australian Mediterranean agro-ecosystems, where soil P availability is naturally low. As legumes tend to require higher P inputs than non-legumes, the ability of these plants to fix N2 under varying soil P levels must be determined. Therefore, the objective of this study was to investigate the influence of soil P supply on plant N status and nodule formation in 11 perennial legumes, including some novel pasture species. We investigated the effect of applying soil P, ranging from 0 to 384 μg P/g dry soil, on plant N status and nodulation in a glasshouse. Without exogenous P supply, shoot N concentration and N : P ratio were higher than at 6 μg P/g soil. Shoot N concentration and N : P ratio then changed little with further increase in P supply. There was a close positive correlation between the number of nodules and shoot P concentration in 7 of the 11 species. Total nodule dry weight and the percentage of plant dry weight that consisted of nodules increased when P supply increased from 6 to 48 μg P/g. Without exogenous P addition, N : P ratios partitioned into a two-group distribution, with species having a N : P ratio of either or g/g. We suggest that plants with a high N : P ratio may take up N from the soil constitutively, while those with a low N : P ratio may regulate their N uptake in relation to internal P concentration. The flexibility of the novel pasture legumes in this study to adjust their leaf N concentrations under different levels of soil P supplements other published evidence of good growth and high P uptake and P-use efficiency under low soil P supply and suggests their potential as pasture plants in low-P soils in Australian Mediterranean agro-ecosystems warrants further attention.

Plant and microbial strategies to improve the phosphorus efficiency of agriculture

Publisher: Springer Science and Business Media LLC

Date: 03-09-2011

DOI: 10.1007/S11104-011-0950-4

Root morphology acclimation to phosphorus supply by six cultivars of Trifolium subterraneum L

Publisher: Springer Science and Business Media LLC

Date: 19-04-2016

DOI: 10.1007/S11104-016-2869-2

Contrasting communities of arbuscule-forming root symbionts change external critical phosphorus requirements of some annual pasture legumes

Publisher: Elsevier BV

Date: 05-2018

DOI: 10.1016/J.APSOIL.2018.01.009

Survival analysis of germination data in response to temperature for Ornithopus species and other temperate pasture legumes

Publisher: CSIRO Publishing

Date: 22-08-2023

DOI: 10.1071/FP23095

Low-moderate dietary phytoestrogens transiently disrupt spermatogenesis and the seminal plasma proteome in the ram

Publisher: Bioscientifica

Date: 09-02-2023

DOI: 10.1530/REP-22-0432

Abstract: Dietary phytoestrogens disrupt a specific stage of ram spermatogenesis, causing subtle decreases in sperm quality by affecting the expression of pathways involved in the structural integrity of the spermatozoa. This paper demonstrates for the first time that ram reproduction is compromised by oestrogenic pasture, whilst also providing a longitudinal model for the impact of phytoestrogens on male fertility. Compounds with oestrogen-like actions are now common in both the Western diet. The long-term impacts and underlying mechanisms by which oestrogenic compounds alter male reproduction, however, are unclear. To investigate this, we used a longitudinal sheep model examining the impact of oestrogenic pasture consumption on semen quality and production, testicular size, sexual behaviour and the seminal plasma proteome of Merino rams ( n = 20), over a full spermatogenic cycle and in the subsequent breeding season. Throughout the study period, sexual behaviour, sperm production and motility were similar between the exposed and non-exposed rams ( P 0.05). However, between 5 and 8 weeks of exposure to dietary phytoestrogens, rams produced a higher percentage of spermatozoa with a specific malformation of the sperm midpiece and reduced DNA integrity, compared to non-exposed rams ( P 0.001). Investigation into the seminal plasma proteome revealed 93 differentially expressed proteins between phytoestrogen-exposed and control rams ( P 0.05). Exposure to phytoestrogens increased the expression of proteins involved in cellular structure development, actin cytoskeleton reorganisation, regulation of cell function and decreased expression in those related to catabolic processes. The greatest fold changes were in proteins involved in the assembly of the sperm flagella, removal of cytoplasm, spermatid development and maintenance of DNA integrity. After returning to non-oestrogenic pasture, no differences in any measure were observed between treatment groups during the subsequent breeding season. We conclude that dietary phytoestrogens can transiently disrupt specific stages of ram spermatogenesis, causing subtle decreases in sperm quality by affecting the expression of pathways involved in the structural integrity of the spermatozoa.

Physiological and morphological adaptations of herbaceous perennial legumes allow differential access to sources of varyingly soluble phosphate

Publisher: Wiley

Date: 08-11-2015

DOI: 10.1111/PPL.12297

Abstract: The aim of this study was to investigate the capacity of three perennial legume species to access sources of varyingly soluble phosphorus (P) and their associated morphological and physiological adaptations. Two Australian native legumes with pasture potential (Cullen australasicum and Kennedia prostrata) and Medicago sativa cv. SARDI 10 were grown in sand under two P levels (6 and 40 µg P g(-1) ) supplied as Ca(H2 PO4 )2 ·H2 O (Ca-P, highly soluble, used in many fertilizers) or as one of three sparingly soluble forms: Ca10 (OH)2 (PO4 )6 (apatite-P, found in relatively young soils major constituent of rock phosphate), C6 H6 O24 P6 Na12 (inositol-P, the most common form of organic P in soil) and FePO4 (Fe-P, a poorly-available inorganic source of P). All species grew well with soluble P. When 6 µg P g(-1) was supplied as sparingly soluble P, plant dry weight (DW) and P uptake were very low for C. australasicum and M. sativa (0.1-0.4 g DW) with the exception of M. sativa supplied with apatite-P (1.5 g). In contrast, K. prostrata grew well with inositol-P (1.0 g) and Fe-P (0.7 g), and even better with apatite-P (1.7 g), similar to that with Ca-P (1.9 g). Phosphorus uptake at 6 µg P g(-1) was highly correlated with total root length, total rhizosphere carboxylate content and total rhizosphere acid phosphatase (EC 3.1.3.2) activity. These findings provide strong indications that there are opportunities to utilize local Australian legumes in low P pasture systems to access sparingly soluble soil P and increase perennial legume productivity, ersity and sustainability.

Cultivation offers effective management of subterranean clover damping-off and root disease

Publisher: Wiley

Date: 14-02-2017

DOI: 10.1111/GFS.12282

University Of Western Australia

Location: Australia

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Linkage Projects - Grant ID: LP200100341

Start Date: 02-2021

End Date: 01-2025

Amount: $650,000.00

Funder: Australian Research Council

Discovery Projects - Grant ID: DP180103157

Start Date: 2018

End Date: 12-2020

Amount: $313,332.00

Funder: Australian Research Council

Linkage Projects - Grant ID: LP0669766

Start Date: 07-2007

End Date: 06-2011

Amount: $327,000.00

Funder: Australian Research Council

Linkage Infrastructure, Equipment And Facilities - Grant ID: LE0989071

Start Date: 01-2009

End Date: 07-2012

Amount: $600,000.00

Funder: Australian Research Council

ARC Future Fellowships - Grant ID: FT140100103

Start Date: 2015

End Date: 12-2018

Amount: $887,482.00

Funder: Australian Research Council

Linkage Projects - Grant ID: LP210100451

Start Date: 05-2022

End Date: 05-2026

Amount: $957,679.00

Funder: Australian Research Council

Linkage Projects - Grant ID: LP110201130

Start Date: 06-2012

End Date: 12-2015

Amount: $419,000.00

Funder: Australian Research Council

Linkage Projects - Grant ID: LP120200808

Start Date: 01-2013

End Date: 12-2015

Amount: $390,000.00

Funder: Australian Research Council

Industrial Transformation Training Centres - Grant ID: IC190100033

Start Date: 08-2020

End Date: 07-2025

Amount: $3,852,568.00

Funder: Australian Research Council