ORCID Profile
0000-0002-3592-0785
Current Organisation
University of Adelaide
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Publisher: CSIRO Publishing
Date: 1999
DOI: 10.1071/AR98175
Abstract: Surveys were conducted for annual Medicago spp. (medic) pastures in the grain belt of south-west Western Australia during spring 1996 and winter–spring 1997 to determine the relationship of rainfall, cultural practices, soil and plant nutrients, and seedling survival with severity of root disease and numbers of parasitic nematodes. Medic pasture was s led on 116 farms. Most pastures consisted of a single medic variety, viz. Serena, Santiago, Cyprus, or Caliph, whereas about 33% of sites had mixed varieties. Regression analyses showed that high rainfall and application of phosphorus fertilisers were correlated with increased severity of rot in medic tap roots. Crop history and medic variety were not related to the level of root rot. Numbers of Pratylenchusin medic roots were not correlated with the level of tap or lateral root rot, medic variety, rainfall, or with the application of insecticide, fertilisers, or herbicides. Soil with relatively high levels of P, NO3-, or Fe was associated with an increased level of tap root rot. Soils with high pH were associated with reduced tap root rot. Soils with relatively high K were related to severe lateral root rot, whereas relatively high levels of P in soil were associated with reduced lateral root rot. Plants with high levels of tap root rot showed low levels of Mg, whilst low levels of Ca and NO3– in tissues were related to high levels of lateral root rot. High levels of tap root rot were associated with relatively high levels of total N, K, and S, Cu, Zn, Mn, and NO3- in plant tissues. Plants with relatively high levels of lateral root rot had relatively high levels of Cu in shoots. Of the 116 annual Medicago pastures s led, only 1% had adequate Mg content and only 19% had adequate Ca content. However, 83% had higher than adequate levels of Cu, 70% had higher than adequate levels of Mn, and all s les showed more than adequate levels of chloride. Experimental sites of M. polymorpha cv. Serena at 6 farms showed that the percentage survival rate of seedlings was negatively correlated with the severity of tap and lateral root rot in the previous year. These results indicate that in the farms surveyed there is a serious threat to annual medic pastures from root rot fungi. The severity of the disease was partly determined by soil conditions and cultural practices.
Publisher: Turkish Journal of Entomology
Date: 12-11-2020
Publisher: Springer Science and Business Media LLC
Date: 1992
DOI: 10.1071/APP9920147
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.
Publisher: Springer Science and Business Media LLC
Date: 2010
DOI: 10.1071/AP10084
Publisher: Brill
Date: 1991
Publisher: Oxford University Press (OUP)
Date: 05-1991
Publisher: Wiley
Date: 04-1982
Publisher: Scientific Societies
Date: 02-2006
DOI: 10.1094/PD-90-0229
Abstract: Field experiments were conducted in three consecutive years to determine the effect of Dilophospora alopecuri inoculation on the incidence of galls with Rathayibacter toxicus in annual ryegrass (Lolium rigidum). R. toxicus is carried into the grass by the seed gall nematode, Anguina funesta, and colonizes the ovules, displacing the nematodes, and producing the toxin responsible for annual ryegrass toxicity. Treatments included three types of D. alopecuri inoculum (naturally colonized ryegrass, cultures grown on sterilized wheat grain, and spore suspension) applied at different application rates and times. In the first year, naturally colonized ryegrass (30 kg ha -1 ), applied 1 week after the break of season, colonized wheat grain (150 kg ha -1 ) applied once at 1, 4, or 8 weeks or applied three times at 1, 4, and 8 weeks after the break of season, and spore suspension at heading, all significantly reduced the numbers of bacterially colonized galls (by 85 to 96%). In the second and third years, inoculum was applied at various rates and times. There were no significant treatment effects in the second year. In the third year, colonized wheat (450 kg ha -1 ) reduced the number of bacterially colonized galls by 73% and there was a significant negative relationship between inoculation rate of colonized wheat (5.5 to 450 kg ha -1 ) and the number of bacterially colonized galls (r = 0.86, P 0.01). D. alopecuri has potential as a biopesticide for the management of annual ryegrass toxicity, but efficacy could be highly variable depending upon season or site, and uneconomic application rates might be needed.
Publisher: Canadian Science Publishing
Date: 09-2021
Abstract: Freezing as a climatic extreme can contribute to patterns of plant distribution by potentially impacting mechanisms of seed release. Therefore, the impact of freezing on samara release and seed germination in infructescences (cones) of Casuarina cunninghamiana Miq. was assessed. Cones at field moisture content were frozen (22 h) and thawed (2 h) through zero to five cycles. Freezing impaired cone dehiscence and samara release ( % samaras released with ≥2 freezing cycles) and reduced germination from frozen samaras still in the cone (30% to 50% loss in total germination with one to five freezing cycles, respectively). Seed germination from a s le of air-dried samaras was only mildly impacted (10% drop in total germination with five freezing cycles). This vulnerability of C. cunninghamiana to freezing damage, particularly samara release, appears to be a novel finding for woody perennials with fruiting structures that are retained in the canopy during winter. Vulnerability to freezing damage also appears to be a potential factor in species persistence and invasiveness.
Publisher: Brill
Date: 2008
DOI: 10.1163/156854108785787299
Abstract: Six isolates of Australian Aphelenchoidoidea, viz., Laimaphelenchus preissii from native coniferous Callitris preissii trees, L. australis from the common pine plantation trees of Pinus radiata and P. pinaster and L. heidelbergi and two morphospecies of Aphelenchoides (H1 and K1) and Cryptaphelenchus sp. (K2) from diseased P. radiata trees, were studied using light microscopy, scanning electron microscopy and phylogenetic analyses of nearly full length sequences of SSU, D2/D3 expansion segments of LSU rDNA and a fragment of cytochrome oxidase subunit I (COI). Bayesian phylogenetic analyses of SSU, LSU and COI of the six nematode species revealed that none of these Australian aphelenchoidoids was inferred to be closely related to Bursaphelenchus. The selected isolates of Aphelenchoides and Laimaphelenchus used in this study were paraphyletic in all molecular analyses. Cryptaphelenchus sp. (K2) was inferred to be sister to Seinura with SSU sequences.
Publisher: No publisher found
Date: 1992
Publisher: Springer Science and Business Media LLC
Date: 10-2004
DOI: 10.1023/B:JOEC.0000045584.56515.11
Abstract: The phytoecdysteroid, 20-hydroxyecdysone (20E), is a major molting hormone of invertebrates, possibly including nematodes. As 20E is inducible in spinach, the defensive role against plant-parasitic nematodes was investigated. The effects of direct application on nematodes was assessed by treating cereal cyst nematode, Heterodera avenae, juveniles with concentrations of 20E from 8.2 x 10(-8) to 5.2 x 10(-5) M before applying to Triticum aestivum growing in sand. H. avenae, Heterodera schachtii (sugarbeet cyst nematode), Meloidogyne javanica (root-knot nematode), and Pratylenchus neglectus (root lesion nematode) were treated with 5.2 x 10(-5) 20E and incubated in moist sand. To test the protective effects of 20E in plants, the latter three nematodes were applied to Spinacia oleracea in which elevated concentrations of 20E had been induced by methyl jasmonate. Abnormal molting, immobility, reduced invasion, impaired development, and death occurred in nematodes exposed to 20E either directly at concentration above 4.2 x 10(-7) M or in plants. Phytoecdysteroid was found to protect spinach from plant-parasitic nematodes and may confer a mechanism for nematode resistance.
Publisher: CSIRO Publishing
Date: 1994
DOI: 10.1071/AR9940841
Abstract: Biological factors contributing to the decline in the incidence of annual ryegrass toxicity (ARGT) in Western Australia were investigated. Annual ryegrass and soil s les were collected in the area where ARGT outbreaks first occurred in Western Australia, an area where the incidence of ARGT has markedly declined. The nematode vector, Anguina funesta, was found in 68% of s les, whereas the toxigenic bacterium, Clavibacter toxicus, was detected in fewer than 2% of s les. The population densities of the nematode were low, but other attributes assayed were normal. The fungus, Dilophospora alopecuri, also associated with A. funesta, was found at 58% of the s ling sites. The abundance of D. alopecuri suggests that it is an important contributor to decline in ARGT. Therefore, the distribution of D. alopecuri in Western Australia was determined in the following season. D. alopecuri was common in the southerly range of A. funesta, but absent in the northerly range where ARGT outbreaks are still common. In the south, D. alopecuri appears to have displaced C. toxicus and reduced A. funesta populations. The findings suggest that there is potential to use D. alopecuri to control ARGT
Publisher: Springer Science and Business Media LLC
Date: 23-06-2011
Publisher: PAGEPress Publications
Date: 09-03-2022
DOI: 10.4081/NHS.2022.541
Abstract: Diaspores (samaras) of the sheoaks, Casuarina and Allocasuarina, have a mesocarp composed of hydrophilic fibres that, in Allocasuarina, rapidly expand on wetting, capturing significant quantities of water. The ecological function of this water capturing has been the subject of speculation but not quantification or experimentation. Therefore, the rate and quantity of water absorbed, and the floatation properties of samaras of accessions of Casuarina and Allocasuarina were assessed. Casuarina absorbed water slowly (~48 h) with median absorption of 90% (by weight) whereas Allocasuarina absorbed water rapidly ( min) with median absorption of 240%. The process was reversible and increasing in Allocasuarina, with median absorption reaching 400% over three to five wetting/drying cycles. The floating half-life of Casuarina and Allocasuarina samaras overlapped, 17-70 and 29-57 h, respectively, so Casuarina samaras were not shown to be better adapted to hydrochory. Based on five accessions of each genus, it does not be appear that water-capturing of sheoak samaras is directly related to habitat aridity, nor to potential hydrochory. Therefore, the ecological implications of differential water-capturing of sheoak samaras remains to be determined.
Publisher: Scientific Societies
Date: 03-2002
DOI: 10.1094/PHYTO.2002.92.3.321
Abstract: Modeling techniques were developed to quantify the probability of Tilletia indica entering and establishing in Western Australia (WA), and to simulate spread, containment, and the economic impact of the pathogen. Entry of T. indica is most likely to occur through imports of bulk grain or fertilizer (0.023 ± 0.017 entries per year and approximately 0.009 ± 0.009 establishments per year). Entry may also occur through straw goods, new or second-hand agricultural machinery, and on personal effects of travelers who have visited regions with infected plants. The combined probability of entry and establishment of T. indica, for all pathways of entry, is about one entry every 25 years and one establishment every 67 years. Alternatively, sensitivity analysis does show that increases in quarantine funding can reduce the probability of entry to about one entry every 50 years and less than one establishment every 100 years. T. indica is spread efficiently through contaminated farm machinery, seed and soil, rain, air currents, and animals. Depending on the rate of spread of the pathogen and the amount of resources allocated for detection, the time until first detection could range from 4 to 11 years and the economic impact could range from 8 to 24% of the total value of wheat production in WA.
Publisher: Springer Science and Business Media LLC
Date: 2010
DOI: 10.1071/AP09050
Publisher: American Society of Agronomy, Crop Science Society of America, Soil Science Society of America
Date: 1996
Publisher: Springer Science and Business Media LLC
Date: 03-05-2021
Publisher: Informa UK Limited
Date: 2004
DOI: 10.1071/MR03010
Publisher: Brill
Date: 1991
Publisher: Springer Science and Business Media LLC
Date: 27-10-2016
Publisher: Elsevier BV
Date: 02-2003
Publisher: Informa UK Limited
Date: 2006
Publisher: Emerald
Date: 05-01-2022
Abstract: With the current dynamics of scientific publishing increasingly driven by citation metrics, it is quite possible this will lead to the loss of some lower-ranked journals as they will be undervalued by authors, research institutions and research funders. This has been specifically predicted for natural science journals, but the efforts of editors of such journals to improve reputation have not been quantitatively assessed. This research aimed to fill this knowledge gap and assess the potential vulnerability of lower-ranked botany journals. Changes in article citation rates since 2009 for 21 lower-ranked general botany journals were examined by least squares linear regression and factors potentially predictive of higher citation potential by principal component analysis. The findings were then examined in a case study of the publishing that followed the celebrated discovery of a living-fossil plant ( Wollemia nobilis ) in the mid-1990s. Article citation rates steadily declined across most of these 21 journals over the period, and if submissions had been favoured (directly or indirectly) for citation potential, this appears to have been an ineffective, perhaps even a flawed, endeavour. Analysis of quantifiable article attributes across a subset of these journals revealed inconsistent relationships with no predictive value for citation potential. The case study clearly highlighted some processes contributing to declining citation rates and the value of botanical reporting well beyond that indicated by citation metrics. It is not possible to know how important prediction of citation potential (directly or indirectly) is when journal editors accept papers for review or publication (such information is not made public, and this might not be a formalised process), so this study is only based what is considered (by the author) to be a reasonable assumption that all journals aim to improve their reputation and use citation metrics as one determinant of this. Unless we give value to lower-ranked regional botany journals in other ways than citations, the current trends in citation rates could lead to the diminution, even loss, of their valuable contribution bio ersity conservation. Although concerns have been expressed about the long-term viability of natural history journals, this is the first research to examine this quantitatively using citation metrics.
Publisher: Informa UK Limited
Date: 2007
Publisher: Brill
Date: 2001
DOI: 10.1163/156854101300106856
Abstract: Large population densities (more than 100 000 per g dry weight of roots) of Radopholus nativus apparently caused economic damage to wheat near Wyalkatchem, Western Australia. Plants in large areas of poor growth were colonised by R. nativus, whereas in areas of better growth Pratylenchus neglectus occurred at lower population densities. The boundary between the areas was distinct. In the same year (1998), a further nine wheat s les were found to be infested with R. nativus through examination of 300 diagnostic s les submitted by Western Australian growers. Mixed Radopholus/Pratylenchus populations occurred in six of those s les. Populations of R. nativus were widely dispersed throughout the cropping areas of the State. It is concluded that R. nativus has the potential under certain conditions and/or crop rotations to reach high population density and cause economic loss.
Publisher: Springer Science and Business Media LLC
Date: 1996
DOI: 10.1071/AP96047
Publisher: Brill
Date: 2004
DOI: 10.1163/156854104323073008
Abstract: Anguina woodi sp. n. was found in galls on dune grass, Ehrharta villosa var. villosa, on Milnerton Beach, South Africa. Mature galls varied in colour from purplish to brown and formed elongated to round elevations on the stems, leaf sheaths and, occasionally, the leaf blades. The adult females of Anguina woodi sp. n. are 1.6-2.7 mm long and coiled into a circle or spiral. Adult males were 1.4-2.1 mm long, straight or slightly curved ventrad or dorsad. Second-stage juveniles (J2) were more or less straight with a prominent mucro on the tail. A few larger juveniles, probably J3 and J4, with developing gonads were also found. Morphological, morphometric and molecular analyses showed that Anguina woodi sp. n. is closely related to A. australis Steiner, 1940 and, to a lesser extent, to A. microlaenae (Fawcett, 1938) Steiner, 1940. From A. australis it differs mainly in a slightly longer female stylet (9.5-15.5 vs 8.0-11.1 μm) and wider female head (8.6-11 vs 7.4 μm) a slightly longer male stylet (10.5-12.0 vs 10-11 μm) and longer spicule (33-36 vs 26.5-35.3 μm), and a longer tail (72-96 vs 49-68 μm) and slightly higher c-value (7.3-12 vs 6.1-8.1) in the J2. The mucro on the tail tip of the J2 of A. woodi sp. n. is also more prominent and, on average, longer than the mucro in A. australis (3.3 vs 1.5 μm). Anguina woodi sp. n. differs from A. microlaenae mainly in the appearance of the galls incited (roundish elevations attached to the substrate by a flattened base vs pedunculate galls attached to the substrate by a narrow base), a longer stylet in both females and males (8-9 μm long in females and males of A. microlaenae), body of male curved ventrad or dorsad in A. woodi sp. n. (dorsad in males of A. microlaenae) and female tail in A. woodi sp. n. tapering gradually to a sub-acute tip vs a prominent peg-like process in A. microlaenae. Phylogenetic analysis of the ITS1 sequences of 19 anguinid populations and species using maximum parsimony and maximum likelihood methods revealed that A. woodi sp. n. clustered with high bootstrap support with A. australis. The ITS1-5.8S-ITS2 fragment sequence differed between these species by 20 nucleotides (2.6%). The J2 of A. australis is herein described for the first time and is compared with the J2 of A. woodi sp. n. Phylogenetic relationships of A. woodi sp. n. with other anguinids parasitising grasses are presented.
Publisher: Microbiology Society
Date: 11-1988
Publisher: Turkish Science and Technology Publishing (TURSTEP)
Date: 30-12-2022
DOI: 10.24925/TURJAF.V10ISP2.2961-2965.5583
Abstract: Trees in upland, semiarid agroecological zones typically require water efficiency due to low rainfall, cold and dry temperatures as in Niğde Province, Central Anatolia, Türkiye. This study quantitatively assessed farmer perception of ecosystem services and production advantage of trees in a semiarid zone. Forty-nine farmers in Niğde Province were surveyed. The survey evaluated two major factors: ecosystem services and production advantage using eleven indicators. The responses were grouped by age, gender, education, district class (rural and urban) and farm settlement (rural and urban) and were analysed by test of association (χ2) at P≤0.05. Most farmers had knowledge of trees in their environment and mainly supported the perspective that trees were important mainly for cultural and provisioning ecosystem services. However, they held the opinion that having trees on their farmer was a production disadvantage in a semiarid agroecological zone. Although there were no gender differences in their perspectives, there were significant difference by age, education, district class and farm settlement. Farmers in this semiarid agroecological zone seemed more interested in trees with evident ecosystem services and production advantage such as improved crop yield, water efficiency, weed and pest management, ease of harvesting as well as reduced overall production cost. By implication, trees with multiple benefits are required if further planting by farmers is to be encouraged for agroecosystem improvement. In addition, tree choice will be based on farmer perception of the benefits of trees for ecosystem services and production advantage and further research to identify and promote trees that benefits the widest range of agroecosystems.
Publisher: Scientific Societies
Date: 02-2014
DOI: 10.1094/PHYTO-12-12-0345-R
Abstract: Lines from a cross between two wheat (Triticum aestivum) cultivars with contrasting resistance phenotypes to Pratylenchus thornei (Nematoda) were investigated to determine the stage at which resistance occurs. Host resistance was examined at nematode attraction to and penetration of roots and nematode motility, maturation, and reproduction within roots. There was no significant difference in the rate at which P. thornei was attracted toward or penetrated resistant or susceptible roots. However, suppression of migration, juvenile maturation, and reproduction in and near resistant roots was evident, suggesting that resistance acts post penetration. No preferential root penetration zone was observed in contrast to other studies. The inhibitory compounds from resistant wheat plants appeared to be constitutively expressed and water soluble because nematode migration was suppressed in roots and root exudates of unchallenged seedlings. The effects of these compounds were reversible and affected P. thornei but not P. neglectus. Apart from migration, nematode multiplication was greatly inhibited by resistance because only a few juveniles (10%) developed past stage three in roots of resistant compared with susceptible plants. Earlier in the life cycle, egg deposition and hatch of P. thornei were also significantly reduced in resistant roots and root exudates, suggesting the presence of hatching inhibitors.
Publisher: Springer Science and Business Media LLC
Date: 2001
DOI: 10.1071/AP01048
Publisher: Springer Science and Business Media LLC
Date: 11-12-2010
Publisher: Wiley
Date: 10-1991
Publisher: Springer Science and Business Media LLC
Date: 19-03-2007
DOI: 10.1007/S00239-006-0187-7
Abstract: We sequenced four mitochondrial subgenomes from the potato cyst nematode Globodera pallida, previously characterized as one of the few animals to have a multipartite mitochondrial genome. The sequence data indicate that three of these subgenomic mitochondrial circles are mosaics, comprising long, multigenic fragments derived from fragments of the other circles. This pattern is consistent with the operation of intermitochondrial recombination, a process generally considered absent in animal mitochondria. We also report that many of the duplicated genes contain deleterious mutations, ones likely to render the gene nonfunctional gene conversion does not appear to be homogenizing the different gene copies. The proposed nonfunctional copies are clustered on particular circles, whereas copies that are likely to code functional gene products are clustered on others.
Publisher: Springer Science and Business Media LLC
Date: 2001
DOI: 10.1071/AP01046
Publisher: Scientific Societies
Date: 11-2004
DOI: 10.1094/PHYTO.2004.94.11.1207
Abstract: The induction of defense compounds in oats (Avena sativa) in response to invasion by parasitic nematodes and to application of the wound hormone methyl jasmonate was examined. Oats cv. Quoll seedlings were challenged with Pratylenchus neglectus, Heterodera avenae, and Ditylenchus dipsaci and treated with 1 × 10 -4 M methyl jasmonate. Three compounds, isolated in methanolic root and shoot extracts of oats, exhibiting an absorbance spectrum typical of flavone glycosides, were induced by nematode invasion and methyl jasmonate. These were identified as flavone-C-glycosides by mass spectrometry. The effect of the flavone-C-glycosides on the invasion by and development of cereal cyst nematode H. avenae was assessed using methanolic extracts of shoots and roots from methyl jasmonate-treated plants. Both extracts impaired nematode invasion and development. When the extracts were fractionated by high voltage paper electrophoresis, only one flavone-C-glycoside, O-methyl-apigenin-C-deoxyhexoside-O-hexoside, inhibited nematode invasion. The protective effect of the induction of flavone-C-glycosides in oats by methyl jasmonate was evaluated against H. avenae and P. neglectus. Treatment with methyl jasmonate reduced invasion of both nematodes and increased plant mass, compensating for damage caused by the nematodes, and is attributed to the active flavone-C-glycoside. The active compound, O-methyl-apigenin-C-deoxyhexoside-O-hexoside, has not been implicated previously in plant defense against any pest or pathogen, and appears to provide protection against the major cereal nematodes Heterodera and Pratylenchus.
Publisher: Wiley
Date: 02-10-2011
Publisher: CSIRO Publishing
Date: 2005
DOI: 10.1071/EA04012
Abstract: The ability of 31 isolates of Dilophospora alopecuri to colonise Lolium rigidum co-inoculated with Anguina funesta and grown in pots outdoors was tested over 2 years. The isolates were collected from 3 grass hosts from sites across the southern mainland states of Australia. Marked variation among isolates of different host and regional origins was found. Isolates from L. rigidum showed the greatest colonisation with a mean of 16 infected inflorescences per 240 mm pot containing 32 plants. Isolates from the other hosts, Avena sativa, Holcus lanatus and Polypogon monspeliensis, only resulted in means of 1.9, 7.7 and 1.3 infected inflorescences per pot, respectively. The data allow selection of an aggressive isolate for dissemination for antagonism of A. funesta, one of the causal agents for annual ryegrass toxicity.
Publisher: The American Phytopathological Society
Date: 2017
Publisher: Wiley
Date: 07-1985
Publisher: Brill
Date: 1988
Publisher: Engineering Sciences Press
Date: 2021
Publisher: Wiley
Date: 10-2008
Publisher: Springer Science and Business Media LLC
Date: 2008
DOI: 10.1071/AP08022
Publisher: CSIRO Publishing
Date: 2002
DOI: 10.1071/EA01054
Abstract: Soil s les were collected in Western Australia from cereal fields at about harvest time to determine levels of the endoparasitic nematodes, Pratylenchus and Heterodera. A systematic survey in 1997 and 1998 centred on the 40 shires with the highest proportion of cereal cropping. One hundred and eighty s les were collected in 1997 and 227 in 1998 at 10-km intervals along north–south transects 35 km apart. A targeted survey in 1997 included 98 soil s les from fields selected by growers as having poor productivity without an evident cause. No Heterodera cysts were found in any survey s le but these could be extracted from soils previously known to be infested. Pratylenchus neglectus was most commonly detected followed by P. thornei and P. zeae. Populations identified as P. brachyurus, P. penetrans, P. scribneri, and an undescribed species similar to P. thornei were also found. Overall Pratylenchus was extracted from 63% of s les (mean 1.1, median 0.3, max. 22.0/mL of soil). Maps of the data indicate that Pratylenchus populations were aggregated with some areas having relatively light infestations. There was a positive relationship with the intensity of cereal cropping and a negative relationship with pulse cropping. The findings indicate that potentially damaging Pratylenchus numbers occur in a significant proportion of fields and highlight the need to develop and implement strategies to lower population densities.
Publisher: CSIRO Publishing
Date: 2000
DOI: 10.1071/AR99049
Abstract: Asurvey of 30 medic pastures for root-rots was undertaken in Western Australia and pathogenicity tests of representative fungal isolates from roots s led were conducted to determine the main factors contributing to medic decline and the association between those factors. In particular, the contribution of pathogenic fungi and nematodes to medic root-rot in Western Australia was studied. From a total of 30 000 pieces of root plated, 3836 fungal isolates were obtained and identified at least to genus level. Four hundred and seventy-two representative isolates were tested for in vitro pathogenicity in Medicago sphaerocarpos cv. Orion. Of these, 32 were further tested in the glasshouse. The pathogenicity tests indicated that 56% of isolates were capable of causing significant damage to the root system and it is likely that pathogenic fungi are largely responsible for medic root-rot in the field. In contrast, the number of Pratylenchus spp. in the roots was not found to relate to disease symptoms. It is concluded that soil-borne pathogenic fungi such as species of Pythium, Fusarium, and Phoma contribute significantly to medic pasture decline in Western Australia.
Publisher: Microbiology Society
Date: 1992
Publisher: Mediterranean Agricultural Sciences
Date: 12-2021
DOI: 10.29136/MEDITERRANEAN.972937
Abstract: None of the known native actinorhizal species in Turkey, Alnus glutinosa and A. orientalis (Betulaceae), Datisca cannabina (Datiscaceae), Elaeagnus angustifolia and Hippophae rhamnoides (Elaeagnaceae), and the widely-planted exotic Casuarina cunninghamiana (Casuarinaceae), have confirmed records of actinorhizae in Turkey. This study determined the capacity of representative actinorhizal plants in Turkey to form nodules, cluster roots and ectomycorrhizal roots in a typical central Anatolian soil with and without amendment of soil and nodule extracts, as well as in soil from Adana and Izmir. Nodulation was confirmed experimentally for E. angustifolia and C. cunninghamiana in Niğde soil (the latter only with addition Adana or Izmir soil), but only observationally for A. glutinosa during s le collection in Rize. Cluster roots developed strongly in C. cunninghamiana, and likewise ectomycorrhizal roots in Allocasuarina verticillata (included as a reference species) but only to a lesser extent in C. cunninghamiana. The nodulation status of the natives, D. cannabina and H. rhamnoides, remains to be investigated.
Publisher: Springer Science and Business Media LLC
Date: 02-05-2013
Publisher: Brill
Date: 2013
DOI: 10.1163/15685411-00002671
Abstract: A new genus and species of anguinid nematode, Zeatylenchus pittosporum gen. n., sp. n., was recovered from leaves of Pittosporum tenuifolium from Hahei, Coromandel Region, North Island, New Zealand. The genus is characterised by having slender males and females, excretory pore opening near the lips and level with the knobs of the retracted stylet, pharynx with a weak non-muscular median bulb, pharyngeal glands overlapping the intestine, females with a single gonad with a quadricolumella and post-uterine sac and males with slender arcuate spicules and the bursa arising anal body diam. anterior to the cloacal aperture and extending ca 30% of distance to the tail tip. Its feeding does not induce galls, only foliar chlorosis. The species has particular characters, including a short, robust stylet with conus forming ca 40% of stylet length and small rounded compact knobs, and tail offset dorsally with a pointed tip. Molecular phylogeny of near full length small subunit, D2/D3 expansion segments of the large subunit and internal transcribed spacer rRNA genes support the description of Zeatylenchus pittosporum gen. n., sp. n. as a new genus and species.
Publisher: Oxford University Press (OUP)
Date: 24-02-2020
DOI: 10.1111/JAM.14602
Publisher: CSIRO Publishing
Date: 1993
DOI: 10.1071/EA9930861
Abstract: An examination of within-paddock distribution of the nematode (Anguina funesta) and bacterium (Clavibacter toxicus) responsible for annual ryegrass toxicity (ARGT) was undertaken to determine the reliability of farmer-collected s les in determining the risk of ARGT. Areas in Western Australia with a recent history of ARGT outbreaks were selected for study. The results indicate that the distribution of ARGT organisms is patchy in paddocks with low population densities, but as the populations grow they spread throughout the paddock. Populations are not likely to reach toxic levels before they become widespread in the paddock. Farmer-collected s les processed by the ARGT Testing Service procedure were found to be a reliable tool for the management of ARGT in Western Australia.
Publisher: CSIRO Publishing
Date: 2020
DOI: 10.1071/BT19153
Abstract: In addition to samara aerodynamics, mechanisms of samara release will contribute to seed dispersal outcomes. Analysis of species descriptions of Australian members of the Casuarinaceae (sheoaks) indicated cone shrinkage to be a possible mechanism enhancing samara release. However, measurement of cones of nine species of Allocasuarina and Casuarina did not support this hypothesis, but outward movement of samaras both in the field and in oven-dried cones indicated that another mechanism was operating. Microscopic examination revealed that the proximal margins of the bracteoles are involute after drying, and it is postulated that incurving of the bracteoles during drying moves samaras outward against gravity enhancing samara release. This study also revealed inconsistencies in cone and samara metrics between field s les (1–3 specimens for 9 species) and the published descriptions. This could lead to identification uncertainties, and indicates the need to revise the descriptions to more fully encompass the variation in sheoaks across their natural and anthropogenic ranges.
Publisher: Brill
Date: 2011
Abstract: A new genus and species of anguinid nematode, Litylenchus coprosma gen. n., sp. n., was recovered from leaves of Coprosma repens A. Rich. from an amenity planting in Wellington, New Zealand. The genus is characterised by having slender males and slender or semi-obese females, pharynx with a weak non-muscular median bulb, a terminal bulb containing the pharyngeal glands, female with a single gonad having a quadricolumella and post-uterine sac male with arcuate spicules and the bursa arising 1-2 anal body diam. anterior to the cloacal aperture and extending nearly to the tail tip, and does not induce galls, only foliar chlorosis. The species is characterised by having a short, robust stylet with conus forming ca 40% of stylet length and three well developed rounded knobs, secretory/excretory pore opening posterior to the nerve ring, terminal bulb abutting the intestine, and tail tip of variable form. Molecular phylogeny of near full length small subunit, D2/D3 expansion segments of the large subunit and internal transcribed spacer rRNA genes support the description of L. coprosma gen. n., sp. n. as a new genus and species.
Publisher: ALOKI Ltd
Date: 2023
Publisher: Public Library of Science (PLoS)
Date: 05-05-2020
Publisher: Elsevier BV
Date: 2004
DOI: 10.1016/S1055-7903(03)00188-X
Abstract: Phylogenetic relationships among gall-forming plant parasitic nematodes of the subfamily Anguininae are reconstructed by maximum parsimony and maximum likelihood analyses. Sequences of the ITS of rDNA from 53 populations and species of gall-forming nematodes and five populations of the Ditylenchus dipsaci species complex were analysed. The phylogenetic trees strongly support monophyly of the genus Anguina and show nonmonophyly for the genera Mesoanguina and Heteroanguina. Morphological and biological characters are generally congruent with the anguinid groups identified in the rDNA phylogeny. Analyses of evolution of different gall types among anguinids reveal that there are apparent evolutionary trends in gall evolution: from abnormal swelling and growth of infested plant organs toward small localised galls, and from infestation of vegetative toward generative organs. Our study demonstrates that the main anguinid groups are generally associated with host plants belonging to the same or related systematic groups. The comparison of the ITS phylogenies of anguinids parasitising Poaceae and their host grasses shows a high level of cospeciation events.
Publisher: Springer Science and Business Media LLC
Date: 2004
DOI: 10.1071/AP04063
Publisher: Elsevier BV
Date: 05-2009
Publisher: Springer Science and Business Media LLC
Date: 2006
DOI: 10.1071/AP06075
Publisher: CSIRO Publishing
Date: 1994
DOI: 10.1071/EA9940797
Abstract: The phosphorus (P) nutrition of largeseeded chickpea (Cicer arietinum) cv. Macarena grown on Cununurra clay in the Ord River Irrigation Area was studied in field trials and by s ling commercial crops. Response to applied and residual P on a previously uncropped site (site 1) was examined over 2 growing seasons and to applied P on a site with a history of cropping (site 2) in 1 season. At site 1, yield increased with application of up to 50 kg P/ha in the first year and 100 kg P/ha in the second year. There was no significant response in the second year to the P applied in the previous season, probably because of rapid fixation of P in Cununurra clay. At site 2, with a residual soil P level of 24 �g/g (HCO3), no growth response to applied P was observed. The survey of commercial crops included determination of P in soil, foliage, and seed, and the recording of phosphatic fertilisers applied. The data indicate that excessive P fertiliser is applied to many chickpea crops, with only a few crops being inadequately supplied.
Publisher: CSIRO Publishing
Date: 1994
DOI: 10.1071/EA9940633
Abstract: S les of annual ryegrass (Lolium rigidum Gaudin) seed tested for herbicide resistance were examined for seed-galls of Anguina funesta, the nematode vector of Clavihacter toxicus the causal bacterium in annual ryegrass toxicity (ARGT). Of the 246 s les examined, 63% contained galls, with concentrations up to 1400 galls per 10 g of seed. Higher herbicide resistance was associated with increased concentrations of A. funesta. We conclude that use of selective herbicides for ARGT control may have contributed to the rapid development of herbicide resistance.
Publisher: Scientific Societies
Date: 11-2006
Abstract: Rathayibacter toxicus is a nematode-vectored gram-positive bacterium responsible for a gumming disease of grasses and production of a highly potent animal and human toxin that is often fatal to livestock and has a history of occurring in unexpected circumstances. DNA of 22 strains of R. toxicus from Australia were characterized using lified fragment length polymorphism (AFLP) and pulsed-field gel electrophoresis (PFGE). AFLP analysis grouped the 22 strains into three genetic clusters that correspond to their geographic origin. The mean similarity between the three clusters was 85 to 86%. PFGE analysis generated three different banding patterns that enabled typing the strains into three genotypic groups corresponding to the same AFLP clusters. The similarity coefficient was 63 to 81% for XbaI and 79 to 84% for SpeI. AFLP and PFGE analyses exhibited an analogous level of discriminatory power and produced congruent results. PFGE analysis indicated that the R. toxicus genome was represented by a single linear chromosome, estimated to be 2.214 to 2.301 Mb. No plasmids were detected.
Publisher: Scientific Societies
Date: 03-1999
DOI: 10.1094/PDIS.1999.83.3.301D
Abstract: Despite the suitability of climate, Western Australia was one of the few grape (Vitis vinifera L.) growing areas free of grapevine downy mildew (Plasmopara viticola (Berk. & M. A. Curtis) Berl. & De Toni in Sacc.). Area freedom had been maintained by restricting the movement of host material and machinery from outside the state and fungicide use in Western Australia vineyards had been considerably less. P. viticola was detected in 1997 in 14 of 15 vines growing at Kalumburu, a remote community in the semi-arid tropics of Western Australia, and was eradicated. In October 1998, grape leaves with oilspots typical of downy mildew were received from a grower in the Swan Valley near Perth, one of the main production areas of Western Australia. Sporangia were hyaline and ellipsoid (14 × 11 μm), were borne on treelike sporangiophores, and were consistent with those described for P. viticola (1). This is the first record of P. viticola in commercial viticulture in Western Australia. A response plan for exotic diseases was activated and after 2 weeks of surveillance the disease was found in 45 of 70 vineyards surveyed of the 280 vineyards in the Swan Valley. Given the extent of spread, eradication of downy mildew was not considered possible. Weather data for August to October 1998 indicated the likelihood of several infection periods from budburst to flowering when the disease was first detected. Crop loss will be considerable in many vineyards. P. viticola was also found in bench-grafted cuttings in pots in leaf consigned from the Swan Valley to several other areas in August 1998. Downy mildew was found in other areas only in association with these consigned vines. An industry code of practice, including hygiene, is being developed to slow the rate of spread of P. viticola in Western Australia. Reference: (1) Anon. C.M.I. Descriptions of Pathogenic Fungi and Bacteria No. 980, 1989.
Publisher: Wiley
Date: 10-1995
Publisher: Springer Science and Business Media LLC
Date: 22-02-2011
Publisher: Brill
Date: 1990
Publisher: Anatolian Journal of Botany
Date: 15-11-2021
DOI: 10.30616/AJB.979577
Abstract: The Australian tree, Casuarina cunninghamiana Miq. (Casuarinaceae), is widely planted for agroecosystem and other benefits, and belongs to a family (sheoaks) with wide adaptation and tolerance to environmental extremes. However, extreme cold as a stressor is not common on the Australian continent, so compared to heat and drought, less work has been done on the cold tolerance of Australian flora. Therefore, saplings of C. cunninghamiana were exposed to 0 to 4 months of extreme winter temperatures below -5°C to about -15°C over 2 years in Niğde, Central Anatolia, Turkey to test their cold sensitvity. Damage was severe, however, most plants exposed to 1 or 2 months of the milder temperatures (down to -5°C) at the beginning of winter recovered. Four months exposure killed all the plants. However, even the milder, early-winter conditions are unlikely to be suitable for the long-term productivity or survival of C. cunninghamiana and perhaps all members of its family. The risk of extreme cold needs to be considered when planting sheoaks beyond their native range.
Publisher: Informa UK Limited
Date: 2009
Publisher: CSIRO Publishing
Date: 2020
DOI: 10.1071/BT19181
Abstract: Insect galls formed within the infructescences (cones) of Allocasuarina luehmannii and Casuarina pauper in southern New South Wales, Australia, are described. The galling was internal within the infested cones, which were small and irregularly developed, but could appear superficially normal except that they had a higher than normal proportion of samaras retained on bracteole dehiscence. Cross-sections revealed abnormal morphology and wasp larval chambers. All exit holes found were between bracteole pairs of either fertile or infertile florets. Emergent wasps were tentatively identified as Eurytoma sp. sensu lato (Hymenoptera: Eurytomidae). These cryptically galled infructescences represent a previously undescribed gall type in the Casuarinaceae and, for Eurytoma, potentially a rare instance of phytophagy in Australia. Infested cones were found in a season when normal cones in this drought affected area were not easily found. It was concluded that this phytophagy could negatively impact the regeneration potential of two already compromised sheoak species.
Publisher: Springer Science and Business Media LLC
Date: 2001
DOI: 10.1071/AP01024
Publisher: Elsevier BV
Date: 1985
Publisher: Wiley
Date: 07-1985
Publisher: Wiley
Date: 1979
Publisher: Elsevier BV
Date: 03-1998
Publisher: Springer Science and Business Media LLC
Date: 2003
DOI: 10.1071/AP02070
No related grants have been discovered for Ian Timothy Riley.