ORCID Profile
0000-0002-3792-4229
Current Organisation
University of Queensland
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Nanomaterials | Crop and Pasture Protection (Pests, Diseases and Weeds) | Horticultural Crop Protection (Pests, Diseases and Weeds) | Crop and Pasture Production |
Control of Plant Pests, Diseases and Exotic Species in Farmland, Arable Cropland and Permanent Cropland Environments | Clay Products
Publisher: Springer Science and Business Media LLC
Date: 07-2002
DOI: 10.1007/S00122-002-0909-1
Abstract: A genetic linkage map of mungbean ( Vigna radiata, 2n = 2 x = 22) consisting of 255 RFLP loci was developed using a recombinant inbred population of 80 in iduals. The population was derived from an inter-subspecific cross between the cultivated mungbean variety 'Berken' and a wild mungbean genotype 'ACC 41' ( V. radiata subsp. sublobata). The total length of the map, which comprised 13 linkage groups, spanned 737.9 cM with an average distance between markers of 3.0 cM and a maximum distance between linked markers of 15.4 cM. The mungbean map was compared to a previously published map of lablab ( Lablab purpureus, 2n = 2 x = 24) using a common set of 65 RFLP probes. In contrast to some other comparative mapping studies among members of the Fabaceae, where a high level of chromosomal rearrangement has been observed, marker order between mungbean and lablab was found to be highly conserved. However, the two genomes have apparently accumulated a large number of duplications/deletions after they erged.
Publisher: Springer Science and Business Media LLC
Date: 2010
DOI: 10.1071/AP10001
Publisher: Springer Science and Business Media LLC
Date: 15-05-2008
DOI: 10.1007/S00122-008-0781-8
Abstract: Sorghum ergot, caused predominantly by Claviceps africana Frederickson, Mantle, de Milliano, is a significant threat to the sorghum industry worldwide. The objectives of this study were firstly, to identify molecular markers linked to ergot resistance and to two pollen traits, pollen quantity (PQ) and pollen viability (PV), and secondly, to assess the relationship between the two pollen traits and ergot resistance in sorghum. A genetic linkage map of sorghum RIL population R931945-2-2 x IS 8525 (resistance source) was constructed using 303 markers including 36 SSR, 117 AFLP , 148 DArT and two morphological trait loci. Composite interval mapping identified nine, five, and four QTL linked to molecular markers for percentage ergot infection (PCERGOT), PQ and PV, respectively, at a LOD >2.0. Co-location/linkage of QTL were identified on four chromosomes while other QTL for the three traits mapped independently, indicating that both pollen and non pollen-based mechanisms of ergot resistance were operating in this sorghum population. Of the nine QTL identified for PCERGOT, five were identified using the overall data set while four were specific to the group data sets defined by temperature and humidity. QTL identified on SBI-02 and SBI-06 were further validated in additional populations. This is the first report of QTL associated with ergot resistance in sorghum. The markers reported herein could be used for marker-assisted selection for this important disease of sorghum.
Publisher: Elsevier BV
Date: 11-2015
Publisher: Elsevier BV
Date: 12-2008
Publisher: Elsevier BV
Date: 10-2006
DOI: 10.1016/J.MYCRES.2006.07.014
Abstract: Sclerotinia species are sexually reproducing ascomycetes. In the past S. minor and S. sclerotiorum, have been assumed to be homothallic because of the self-fertility of colonies derived from single ascospores. S. trifoliorum has previously been shown to be bipolar heterothallic due to the presence of four self-fertile and four self-sterile ascospores within a single ascus [Uhm, J.Y., Fujii, H., 1983a. Ascospore dimorphism in Sclerotinia trifoliorum and cultural characters of strains from different-sized spores. Phytopathology73: 565-569]. However, isolates of S. minor and S. sclerotiorum were proven to be homothallic ascomycetes, by self-fertility of all eight ascospores within an ascus. Apothecia were raised from all eight ascospores of a single tetrad from four isolates of S. minor and from an isolate of S. sclerotiorum, indicating that inbreeding may be the predominant breeding mechanism of S. minor. Ascospores from asci of S. minor and S. sclerotiorum were predominantly monomorphic, but rare ex les of ascospore dimorphism similar to S. trifoliorum were found.
Publisher: Elsevier BV
Date: 11-2002
Publisher: Frontiers Media SA
Date: 31-05-2019
Publisher: Elsevier BV
Date: 11-2021
DOI: 10.1016/J.MIMET.2021.106342
Abstract: Robust antifungal screening is technically challenging particularly for filamentous fungi. We present a method for undertaking antifungal screening assays that builds upon existing broth dilution protocols and incorporates time resolved image-based assessment of fungal growth. We show that the method performs with different fungi, particularly those for which spores can be used as inoculum, and with different compound classes, can accurately assess susceptibility or otherwise in only few hours and can even account for differences in inherent growth properties of strains.
Publisher: Springer Science and Business Media LLC
Date: 24-03-2016
Publisher: Springer New York
Date: 17-10-2018
DOI: 10.1007/978-1-4939-7278-4_4
Abstract: Fusarium spp. are devastating fungal pathogens which cause significant losses in many cereal crops like wheat, maize, and barley. Genetic improvement of disease resistance requires an improved understanding of defense-associated processes operating in the host in response to an attack by Fusarium spp. Brachypodium distachyon is emerging as a model where host-cereal-infecting pathogen interactions can be studied conveniently. However, this requires developing an efficient infection assay that facilitates quick screening of germplasm (e.g., mutant lines). Here, we provide an efficient and reproducible Fusarium infection assay for Brachypodium. We believe this method will help further develop Brachypodium as a model for genetic improvement of disease resistance in cereals against Fusarium pathogens.
Publisher: Microbiology Society
Date: 15-08-2023
Abstract: Ginger (Zingiber officinale Roscoe) is an important horticultural crop valued for its medicinal and culinary properties. Fusarium yellows, caused by the ascomycete fungus Fusarium oxysporum f. sp. zingiberi (Foz) is a devastating soil borne disease of ginger. It has curtailed ginger production in Australia and around the world leading to significant economic losses. An integrated approach is required to manage soil-borne diseases such as those caused by Foz. However, little is known about the influence of Foz inoculum on disease severity. This study aimed to establish a minimum threshold level of spores per gram of soil required for plant infection and to develop and evaluate a pot inoculation method for suitability in screening large number of plants in a controlled environment. To achieve this, the dominant Australian ginger cultivar ‘Canton’ was inoculated with 101, 103, 105, 106, and 107 microconidia per gram of soil. The inoculum density positively associated with leaf and stem yellows, and rhizome discolouration, and negatively associated with root length and rhizome weight. The lowest threshold required for plant infection was 101 microconidia per gram of soil, which may provide an important basis for outbreaks of Foz in the field. This finding adds significantly to the knowledge of the impact of soil health to ginger production thereby contributing to the integrated management of Foz. When used at a high dose, this method can facilitate reliable and accurate screening of Foz susceptible ginger genotypes in a controlled environment.
Publisher: Microbiology Society
Date: 09-2023
Publisher: Frontiers Media SA
Date: 27-11-2018
Publisher: Wiley
Date: 10-11-2018
DOI: 10.1111/MPP.12594
Publisher: Microbiology Society
Date: 11-08-2023
Abstract: Ginger (Zingiber officinale Roscoe) is an important horticulture crop valued for its medicinal and culinary properties. Fusarium yellows, caused by the ascomycete fungus Fusarium oxysporum f. sp. zingiberi (Foz) is a devastating soil borne disease of ginger. It has curtailed ginger production in Australia and around the world leading to significant economic losses. An integrated approach is required to manage soil-borne diseases such as those caused by Foz. Little is known about the influence of Foz inoculum dosage on disease severity. This study aimed to establish a minimum threshold level of spores per gram of soil required for plant infection and to develop and evaluate a pot inoculation method for suitability in genetic studies on Foz resistance. To achieve this, the dominant Australian ginger cultivar ‘Canton’ was inoculated with pre-determined amounts of colony-forming unit (cfu), ranging from 0 in control, to treatments with 10, 103, 105, 106, and 107 cfu per gram of soil. The inoculum dosage positively correlated with leaf and stem yellows, and rhizome discolouration, and negatively correlated with root length and rhizome weight. The lowest threshold required for plant infection was 10 cfu per gram of soil, which may provide an important basis for outbreaks of Foz in the field. This finding adds significantly to the knowledge base on ginger soil health and contributes to the integrated management of Foz. When used at a high dose, this method can facilitate reliable and accurate screening of Foz susceptible ginger genotypes in a controlled environment.
Publisher: Springer Science and Business Media LLC
Date: 19-06-2021
Publisher: MDPI AG
Date: 02-03-2021
DOI: 10.3390/IJMS22052508
Abstract: During the infection of a host, plant pathogenic fungi secrete small proteins called effectors, which then modulate the defence response of the host. In the Fusarium oxysporum species complex (FOSC), the secreted in xylem (SIX) gene effectors are important for host-specific pathogenicity, and are also useful markers for identifying the various host-specific lineages. While the presence and ersity of the SIX genes has been explored in many of the pathogenic lineages of F. oxysporum, there is a limited understanding of these genes in non-pathogenic, endophytic isolates of F. oxysporum. In this study, universal primers for each of the known SIX genes are designed and used to screen a panel of endophytically-associated Fusarium species isolated from healthy, asymptomatic banana tissue. SIX gene orthologues are identified in the majority of the Fusarium isolates screened in this study. Furthermore, the SIX gene profiles of these endophytic isolates do not overlap with the SIX genes present in the pathogenic lineages of F. oxysporum that are assessed in this study. SIX gene orthologues have not been commonly identified in Fusarium species outside of the FOSC nor in non-pathogenic isolates of F. oxysporum. The results of this study indicate that the SIX gene effectors may be more broadly distributed throughout the Fusarium genus than previously thought. This has important implications for understanding the evolution of pathogenicity in the FOSC.
Publisher: Wiley
Date: 11-2006
Publisher: Springer Science and Business Media LLC
Date: 13-05-2014
Publisher: Wiley
Date: 07-07-2011
DOI: 10.1002/PTR.3563
Abstract: Basidiomycetous macrofungi have therapeutic potential due to antimicrobial activity but little information is available for Australian macrofungi. Therefore, the present study investigated 12 Australian basidiomycetous macrofungi, previously shown to have promising activity against Staphylococcus aureus and Escherichia coli, for their antimicrobial potential against a range of other clinically relevant micro-organisms. Fruiting bodies were collected from across Queensland, Australia, freeze-dried and sequentially extracted with water and ethanol. The crude extracts were tested at 10 mg/mL and 1 mg/mL against six pathogens including two Gram-positive and two Gram-negative bacteria along with two fungi using a high throughput 96-well microplate bioassay. A degree of specificity in activity was exhibited by the water extract of Ramaria sp. (Gomphaceae) and the ethanol extracts of Psathyrella sp. (Psathyrellaceae) and Hohenbuehelia sp., which inhibited the growth of the two fungal pathogens used in the assay. Similarly, the ethanol extract of Fomitopsis lilacinogilva (Fomitopsidaceae) was active against the Gram-positive bacteria B. cereus only. Activity against a wider range of the microorganisms used in the assay was exhibited by the ethanol extract of Ramaria sp. and the water extract of Hohenbuehelia sp. (Pleurotaceae). These macrofungi can serve as new sources for the discovery and development of much needed new antimicrobials.
Publisher: Wiley
Date: 1997
Abstract: Microsatellites or simple sequence repeats (SSRs) are ubiquitous in eukaryotic genomes. Single-locus SSR markers have been developed for a number of species, although there is a major bottleneck in developing SSR markers whereby flanking sequences must be known to design 5'-anchors for polymerase chain reaction (PCR) primers. Inter SSR (ISSR) fingerprinting was developed such that no sequence knowledge was required. Primers based on a repeat sequence, such as (CA)n, can be made with a degenerate 3'-anchor, such as (CA)8RG or (AGC)6TY. The resultant PCR reaction lifies the sequence between two SSRs, yielding a multilocus marker system useful for fingerprinting, ersity analysis and genome mapping. PCR products are radiolabelled with 32P or 33P via end-labelling or PCR incorporation, and separated on a polyacrylamide sequencing gel prior to autoradiographic visualisation. A typical reaction yields 20-100 bands per lane depending on the species and primer. We have used ISSR fingerprinting in a number of plant species, and report here some results on two important tropical species, sorghum and banana. Previous investigators have demonstrated that ISSR analysis usually detects a higher level of polymorphism than that detected with restriction fragment length polymorphism (RFLP) or random lified polymorphic DNA (RAPD) analyses. Our data indicate that this is not a result of greater polymorphism genetically, but rather technical reasons related to the detection methodology used for ISSR analysis.
Publisher: Wiley
Date: 08-07-2008
DOI: 10.1111/J.1439-0434.2008.01396.X
Abstract: A study was undertaken to investigate the potential sources of Pythium inoculum in greenhouse soils. About 7% of fallow soils were found to harbour Pythium before being introduced into greenhouses. When replacing the top layer (30–60 cm) of cultivated soil in greenhouses with fallow soil, Pythium inoculum was still recovered from the bottom layer of soil left in the greenhouse. Other potential sources of Pythium were found to be potting mixtures and contaminated soil adhering to cultivation equipment, growers’ shoes and reused irrigation pipes. Pythium isolates from different sources were from two species: Pythium aphanidermatum (88%) and P. spinosum (12%). This appears to be the first report of transmission of Pythium via contaminated soil adhering to reused irrigation pipes. It also represents the first report in Oman of transmission of Pythium into greenhouses via potting mixtures and fallow soils.
Publisher: Wiley
Date: 06-1993
Publisher: Springer Science and Business Media LLC
Date: 04-2026
DOI: 10.1071/AP02022
Publisher: Oxford University Press (OUP)
Date: 08-2009
Abstract: Jasmonate signaling plays an important role in both plant defense and development. Here, we have identified a subunit of the Mediator complex as a regulator of the jasmonate signaling pathway in Arabidopsis thaliana. The Mediator complex is a conserved multiprotein complex that acts as a universal adaptor between transcription factors and the RNA polymerase II transcriptional machinery. We report that the PHYTOCHROME AND FLOWERING TIME1 (PFT1) gene, which encodes the MEDIATOR25 subunit of Mediator, is required for jasmonate-dependent defense gene expression and resistance to leaf-infecting necrotrophic fungal pathogens. Conversely, PFT1 appears to confer susceptibility to Fusarium oxysporum, a root-infecting hemibiotrophic fungal pathogen known to hijack jasmonate responses for disease development. Consistent with this, jasmonate gene expression was suppressed in the pft1 mutant during infection with F. oxysporum. In addition, a wheat (Triticum aestivum) homolog of PFT1 complemented the defense and the developmental phenotypes of the pft1 mutant, suggesting that the jasmonate signaling functions of PFT1 may be conserved in higher plants. Overall, our results identify an important control point in the regulation of the jasmonate signaling pathway within the transcriptional machinery.
Publisher: International Society for Horticultural Science (ISHS)
Date: 12-2015
Publisher: Scientific Societies
Date: 09-2008
Abstract: The Old World climbing fern, Lygodium microphyllum (Cav.) R. Br., and Japanese climbing fern, L. japonicum (Thunb.) Sw., are invasive noxious weeds in Florida (1). Exploratory surveys for classical biological control agents of L. microphyllum in the fern's native range of Australia and Asia have focused on aboveground herbivores (1). From February to August 2006, fungi were isolated from symptomatic foliage, including lesions associated with leaf curls caused by the mite Flocarus perrepae Knihinicki & Boczek., obtained from L. microphyllum at sites across southeast Queensland, Australia and from both fern species grown at the CSIRO Long Pocket Laboratories in Brisbane, Australia. Anthracnose symptoms with chlorotic margins, initiating at the tip or base of the in idual pinnules, were observed on fronds. Dieback symptoms affected growing tips, with sunken lesions and a gradual necrotic wilt as far as the next growth junction of pinnae. Sections from diseased margins were surface sterilized, placed onto water agar, and incubated at 23°C with a 16-h photoperiod. Variable colonies of white-to-gray mycelia, felted or tufted with complete margins, grew well on oatmeal agar and potato dextrose agar. Conidia were hyaline to light salmon, aseptate, straight, and cylindrical (10.4 to 18.2 × 2.6 to 5.2 μm), borne in salmon-to-bright orange masses at 25°C, and consistent with previous descriptions of Colletotrichum gloeosporioides (Penz.) Penz. & Sacc. (3), anamorph of Glomerella cingulata (2). Asci that formed after 3 to 4 weeks in culture were eight-spored, clavate to cylindrical (46.8 to 62.4 × 9.1 to 11.7 μm), and thickened at the apex, and ascospores were cylindrical (11.7 to 18.2 × 3.9 to 5.2 μm), slightly curved, unicellular and hyaline, which is consistent with descriptions of G. cingulata (2). No fruiting bodies were observed in planta acervuli, setae, and perethecia were not observed. Identification was further confirmed by molecular analysis using the primer pair ITS1/ITS4 (4) (GenBank Accession No. EU697014), indicating 100% similarity to isolates of G. cingulata. To confirm pathogenicity, Koch's postulates were performed on three plants of L. japonicum and 12 plants of L. microphyllum, with an equal number of controls. Conidial suspensions were made to 1.7 × 10 6 conidia ml –1 . During the experiments in the glasshouse, temperatures ranged from 12.6 to 40°C and relative humidity from 39 to 85%. Tips and fronds were collected after 2 to 8 weeks and isolation and identification performed. G. cingulata was consistently reisolated from diseased tissue. No symptoms appeared on controls and isolations did not yield the pathogen. To our knowledge, this is the first report of G. cingulata infecting L. microphyllum and L. japonicum in Australia. Its potential as a biological control agent in the ferns' introduced range remains to be tested. References: (1) J. A. Goolsby et al. Biol. Control. 28:33, 2003. (2) J. E. M. Mordue. Glomerella cingulata. No. 315 in: CMI Descriptions of Pathogenic Fungi and Bacteria. CAB, Kew, UK, 1971. (3) B. C. Sutton. The Genus Glomerella and its Anamorph Colletotrichum. In: Colletotrichum: Biology, Pathology and Control. J. A. Bailey and M. J. Jeger, eds. CAB International, Wallingford, UK, 1992. (4) T. M. White et al. Amplification and Direct Sequencing of Fungal Ribosomal RNA for Phylogenetics. Page 315 in: PCR Protocols: A Guide to Methods and Applications. M. A. Innis et al., eds. Academic Press, San Diego, 1990.
Publisher: Wiley
Date: 16-09-2007
Publisher: Wiley
Date: 07-11-2012
DOI: 10.1111/JPH.12042
Publisher: Springer Science and Business Media LLC
Date: 02-03-2016
Publisher: Springer Science and Business Media LLC
Date: 2006
DOI: 10.1071/AP06017
Publisher: Springer Science and Business Media LLC
Date: 07-2004
DOI: 10.1023/B:MYCO.0000041833.41085.6F
Abstract: Two species of Ganoderma belonging to different subgenera which cause disease on oil palms in PNG are identified by basidiome morphology and the morphology of their basidiospores. The names G. boninense and G. tornatum have been applied. Significant pleiomorphy was observed in basidiome characters amongst the specimens examined. This variation in most instances did not correlate well with host or host status. Spore morphology appeared uniform within a species and spore indices varied only slightly. G. tornatum was found to have a broad host range whereas G. boninense appears to be restricted to palms in Papua New Guinea.
Publisher: Cold Spring Harbor Laboratory
Date: 19-08-2021
DOI: 10.1101/2021.08.18.456906
Abstract: Robust antifungal screening is technically challenging particularly for filamentous fungi. We present a method for undertaking antifungal screening assays that builds upon existing broth dilution protocols and incorporates time resolved image-based assessment of fungal growth. We show that the method performs with different fungi, particularly those for which spores can be used as inoculum, and with different compound classes, can accurately assess susceptibility or otherwise in only few hours, performs well even without replication and can even account for differences in inherent growth properties of strains.
Publisher: Wiley
Date: 12-05-2013
Publisher: Springer Science and Business Media LLC
Date: 11-05-2013
Publisher: Springer Science and Business Media LLC
Date: 30-03-2014
Publisher: Elsevier BV
Date: 07-2008
Publisher: Scientific Societies
Date: 02-2017
DOI: 10.1094/PDIS-05-16-0614-RE
Abstract: Leaf rust (LR) caused by Puccinia triticina, is among the most important diseases of wheat (Triticum aestivum L.) crops globally. Deployment of cultivars incorporating genetic resistance, such as adult plant resistance (APR) or all-stage resistance, is considered the most sustainable control method. APR is preferred for durability because it places lower selection pressure on the pathogen and is often polygenic. In the search for new sources of APR, here we explored a ersity panel sourced from the N. I. Vavilov Institute of Plant Genetic Resources. Based on DNA marker screening, 83 of the 300 lines were deemed to carry known APR genes namely, Lr34, Lr46, and Lr67. Interestingly, lines carrying Lr67 were mostly landraces from India and Pakistan, reconfirming the likely origin of the gene. Rapid phenotypic screening using a method that integrates assessment at both seedling and adult growth stages under accelerated growth conditions (i.e., constant light and controlled temperature) identified 50 lines carrying APR. Levels of APR corresponded well with phenotypes obtained in a field nursery inoculated using the same pathotype (R 2 = 0.82). The second year of field testing, using a mixture of pathotypes with additional virulence for race-specific APR genes (Lr13 and Lr37), identified a subset of 13 lines that consistently displayed high levels of APR across years and pathotypes. These lines provide useful sources of resistance for future research. A strategy combining rapid generation advance coupled with phenotyping under controlled conditions could accelerate introgression of these potentially novel alleles into adapted genetic backgrounds.
Publisher: Wiley
Date: 02-07-2019
DOI: 10.1111/PPA.13056
Publisher: Frontiers Media SA
Date: 15-05-2019
Publisher: Wiley
Date: 09-1992
Publisher: Canadian Science Publishing
Date: 10-2003
DOI: 10.1139/G03-057
Abstract: A major locus conferring resistance to the causal organism of powdery mildew, Erysiphe polygoni DC, in mungbean (Vigna radiata L. Wilczek) was identified using QTL analysis with a population of 147 recombinant inbred in iduals. The population was derived from a cross between 'Berken', a highly susceptible variety, and ATF 3640, a highly resistant line. To test for response to powdery mildew, F 7 and F 8 lines were inoculated by dispersing decaying mungbean leaves with residual conidia of E. polygoni amongst the young plants to create an artificial epidemic and assayed in a glasshouse facility. To generate a linkage map, 322 RFLP clones were tested against the two parents and 51 of these were selected to screen the mapping population. The 51 probes generated 52 mapped loci, which were used to construct a linkage map spanning 350 cM of the mungbean genome over 10 linkage groups. Using these markers, a single locus was identified that explained up to a maximum of 86% of the total variation in the resistance response to the pathogen.Key words: mungbean, powdery mildew, Erysiphe polygoni, QTL, molecular markers.
Publisher: Wiley
Date: 28-02-2013
DOI: 10.1111/PPA.12047
Publisher: MDPI AG
Date: 04-03-2021
DOI: 10.3390/JOF7030184
Abstract: Fusarium wilt caused by the soil-borne fungus Fusarium oxysporum f.sp. cubense (Foc) is a significant constraint to banana production worldwide, with the recent expansion of banana growing regions impacted by Foc Tropical Race 4 (TR4). The lack of commercially acceptable Cavendish cultivars with Foc resistance means the only current means of effective control is through strict quarantine and inoculum management. One method of control that is currently advocated includes the removal of infected plants which have been killed using herbicide injections. The aim of this work was to examine the effect of herbicide and fungicide treatments on sporulation of the fungus. In glasshouse studies using a green fluorescent transformed Foc Subtropical Race 4 isolate, we found treatments with herbicide hastened colonisation of the banana tissue and the production of micro- and macroconidia. The use of a fungicide did not prevent sporulation of the fungus in such tissue. This study demonstrates that herbicide treated plants are a source of potential inoculum for infection of nearby plants.
Publisher: Springer Science and Business Media LLC
Date: 20-10-2010
DOI: 10.1007/S11230-010-9265-8
Abstract: Radopholus similis is one of the world's ten most economically important plant-parasitic nematodes. It is especially a problem in banana cultivation, where the nematodes' feeding reduces yields and causes toppling disease. It has been suggested that the genus Radopholus Thorne, 1949 might have an Australian origin, but the native range of R. similis (Cobb, 1893) is not well known. Here we undertake a phylogeographical study of s les of R. similis from banana plantations down the eastern seaboard of Australia, with additional s les from Costa Rica and accessions from GenBank, to examine the origin of pest populations of R. similis. The lack of genetic ersity of R. similis within Australia, and its sharing of a worldwide pest haplotype, suggest that populations of R. similis in Australia were introduced from a single source population, most likely from the Southeast Asian region. This might not be the case in Africa, where extensive genetic ersity has been found.
Publisher: Wiley
Date: 08-06-2015
DOI: 10.1111/GCB.12927
Abstract: Warmer temperatures associated with climate change are expected to have a direct impact on plant pathogens, challenging crops and altering plant disease profiles in the future. In this study, we have investigated the effect of increasing temperature on the pathogenic fitness of Fusarium pseudograminearum, an important necrotrophic plant pathogen associated with crown rot disease of wheat in Australia. Eleven wheat lines with different levels of crown rot resistance were artificially inoculated with F. pseudograminearum and maintained at four diurnal temperatures 15/15°C, 20/15°C, 25/15°C and 28/15°C in a controlled glasshouse. To quantify the success of F. pseudograminearum three fitness measures, these being disease severity, pathogen biomass in stem base and flag leaf node, and deoxynivalenol (DON) in stem base and flag leaf node of mature plants were used. F. pseudograminearum showed superior overall fitness at 15/15°C, and this was reduced with increasing temperature. Pathogen fitness was significantly influenced by the level of crown rot resistance of wheat lines, but the influence of line declined with increasing temperature. Lines that exhibited superior crown rot resistance in the field were generally associated with reduced overall pathogen fitness. However, the relative performance of the wheat lines was dependent on the measure of pathogen fitness, and lines that were associated with one reduced measure of pathogen fitness did not always reduce another. There was a strong correlation between DON in stem base tissue and disease severity, but length of browning was not a good predictor of Fusarium biomass in the stem base. We report that a combination of host resistance and rising temperature will reduce pathogen fitness under increasing temperature, but further studies combining the effect of rising CO2 are essential for more realistic assessments.
Publisher: Elsevier BV
Date: 12-2013
Publisher: Wiley
Date: 12-2003
Publisher: Wiley
Date: 05-12-2006
Publisher: Springer Science and Business Media LLC
Date: 2009
DOI: 10.1071/AP08074
Publisher: Springer Science and Business Media LLC
Date: 2007
DOI: 10.1071/AP07062
Publisher: Oxford University Press (OUP)
Date: 09-06-2016
DOI: 10.1093/AOB/MCW095
Publisher: Scientific Societies
Date: 06-2011
Abstract: Fusarium oxysporum is a root-infecting fungal pathogen that causes wilt disease on a broad range of plant species, including the model plant Arabidopsis thaliana. Currently, very little is known about the molecular or physiological processes that are activated in the host during infection and the roles these processes play in resistance and susceptibility to F. oxysporum. In this study, we analyzed global gene expression profiles of F. oxysporum-infected Arabidopsis plants. Genes involved in jasmonate biosynthesis as well as jasmonate-dependent defense were coordinately induced by F. oxysporum. Similarly, tryptophan pathway genes, including those involved in both indole-glucosinolate and auxin biosynthesis, were upregulated in both the leaves and the roots of inoculated plants. Analysis of plants expressing the DR5:GUS construct suggested that root auxin homeostasis was altered during F. oxysporum infection. However, Arabidopsis mutants with altered auxin and tryptophan-derived metabolites such as indole-glucosinolates and camalexin did not show an altered resistance to this pathogen. In contrast, several auxin-signaling mutants were more resistant to F. oxysporum. Chemical or genetic alteration of polar auxin transport also conferred increased pathogen resistance. Our results suggest that, similarly to many other pathogenic and nonpathogenic or beneficial soil organisms, F. oxysporum requires components of auxin signaling and transport to colonize the plant more effectively. Potential mechanisms of auxin signaling and transport-mediated F. oxysporum susceptibility are discussed.
Publisher: Wiley
Date: 23-10-2020
DOI: 10.1111/JEN.12830
Publisher: Scientific Societies
Date: 08-2018
Publisher: Elsevier BV
Date: 03-2020
DOI: 10.1016/J.FGB.2019.103314
Abstract: Fusarium pseudograminearum (Fp), the causative fungal pathogen of the diseases Fusarium crown rot, is an important constraint to cereals production in many countries including Australia. Fp produces a number of secondary metabolites throughout its life cycle. One of these metabolites, the cyclic lipopeptide fusaristatin A, is encoded by a specific gene cluster containing a polyketide synthase and a three-module non-ribosomal peptide synthetase. However, a recent survey of Fp populations across Australia suggests that this cluster may only be present in a subset of isolates from Western Australia (WA). In this study, we screened 319 Fp isolates from WA and 110 Fp isolates from the Australian eastern states of New South Wales, Victoria, Queensland and South Australia to examine the distribution of this gene cluster among Australian Fp populations. The fusaristatin A gene cluster was found to be present in ~50% of Fp isolates from WA but completely absent in Fp isolates from eastern states. To determine its potential function, mutants of the fusaristatin A gene cluster were generated by disrupting the non-ribosomal peptide synthetase and polyketide synthase genes simultaneously in two different parental backgrounds. The mutants showed increased growth rates and were significantly more aggressive than their respective parental strains on wheat in crown rot pathogenicity assays. This suggested that fusaristatin A has a negative effect on fungal development and aggressiveness. The possible reasons for the geographically restricted presence of the fusaristatin A gene cluster and its role in fungal biology are discussed.
Publisher: Wiley
Date: 29-01-2014
DOI: 10.1111/PPA.12184
Publisher: Wiley
Date: 30-01-2014
DOI: 10.1111/PPA.12182
Publisher: Springer Science and Business Media LLC
Date: 11-01-2021
Publisher: Naturalis Biodiversity Center
Date: 31-12-2011
Publisher: Wiley
Date: 23-03-2017
DOI: 10.1111/PPA.12697
Publisher: Oxford University Press (OUP)
Date: 25-08-2017
DOI: 10.1111/LAM.12779
Abstract: Pythium myriotylum is responsible for severe losses in both capsicum and ginger crops in Australia under different regimes. Intraspecific genomic variation within the pathogen might explain the differences in aggressiveness and pathogenicity on erse hosts. In this study, whole genome data of four P. myriotylum isolates recovered from three hosts and one Pythium zingiberis isolate were derived and analysed for sequence ersity based on single nucleotide polymorphisms (SNPs). A higher number of true and unique SNPs occurred in P. myriotylum isolates obtained from ginger with symptoms of Pythium soft rot (PSR) in Australia compared to other P. myriotylum isolates. Overall, SNPs were discovered more in the mitochondrial genome than those in the nuclear genome. Among the SNPs, a single substitution from the cytosine (C) to the thymine (T) in the partially sequenced CoxII gene of 14 representatives of PSR P. myriotylum isolates was within a restriction site of HinP1I enzyme which was used in the PCR-RFLP for detection and identification of the isolates without sequencing. The PCR-RFLP was also sensitive to detect PSR P. myriotylum strains from artificially infected ginger without the need for isolation for pure cultures. This is the first study of intraspecific variants of Pythium myriotylum isolates recovered from different hosts and origins based on single nucleotide polymorphism (SNP) genotyping of multiple genes. The SNPs discovered provide valuable makers for detection and identification of P. myriotylum strains initially isolated from Pythium soft rot (PSR) ginger by using PCR-RFLP of the CoxII locus. The PCR-RFLP was also sensitive to detect P. myriotylum directly from PSR ginger s led from pot trials without the need of isolation for pure cultures.
Publisher: CSIRO Publishing
Date: 1994
DOI: 10.1071/BT9940009
Abstract: Morphological characterisation allows isolates of Colletotrichum gloeosporioides, Colletotrichum musae and Colletotrichum acutatum to be identified only to species level. Pathogenicity tests and random lified polymorphic DNA (RAPD) markers distinguished a mango biotype of C. gloeosporioides from eight other isolates of C gloeosporioides obtained from five different fruit species. Using these procedures, it was also possible to distinguish C. acutatum and C. musae both from each other, and from the C. gloeosporioides isolates. In cross-infectivity studies, isolates of C. gloeosporioides displayed a wide host range with the exception of isolates from mango, which were highly virulent on mango only. Teleomorphic isolates of C. gloeosporioides were clustered together by RAPD analysis. This work has demonstrated the existence of a biotype of C. gloeosporioides which shows specialisation to mango.
Publisher: Wiley
Date: 12-2003
Publisher: Springer Science and Business Media LLC
Date: 09-06-2018
Publisher: Springer Science and Business Media LLC
Date: 10-11-2012
Publisher: Wiley
Date: 06-2005
Publisher: Springer Science and Business Media LLC
Date: 11-02-2017
Publisher: Springer Science and Business Media LLC
Date: 24-06-2016
Publisher: Elsevier BV
Date: 11-2014
Publisher: Springer Science and Business Media LLC
Date: 03-02-2022
DOI: 10.1007/S00122-022-04037-8
Abstract: Multi-year evaluation of the Vavilov wheat ersity panel identified new sources of adult plant resistance to stripe rust. Genome-wide association studies revealed the key genomic regions influencing resistance, including seven novel loci. Wheat stripe rust (YR) caused by Puccinia striiformis f. sp . tritici ( Pst ) poses a significant threat to global food security. Resistance genes commonly found in many wheat varieties have been rendered ineffective due to the rapid evolution of the pathogen. To identify novel sources of adult plant resistance (APR), 292 accessions from the N.I. Vavilov Institute of Plant Genetic Resources, Saint Petersburg, Russia, were screened for known APR genes (i.e. Yr18 , Yr29 , Yr46 , Yr33 , Yr39 and Yr59 ) using linked polymerase chain reaction (PCR) molecular markers. Accessions were evaluated against Pst (pathotype 134 E16 A + Yr17 + Yr27) at seedling and adult plant stages across multiple years (2014, 2015 and 2016) in Australia. Phenotypic analyses identified 132 lines that potentially carry novel sources of APR to YR. Genome-wide association studies (GWAS) identified 68 significant marker–trait associations ( P 0.001) for YR resistance, representing 47 independent quantitative trait loci (QTL) regions. Fourteen genomic regions overlapped with previously reported Yr genes, including Yr29 , Yr56 , Yr5 , Yr43 , Yr57 , Yr30 , Yr46, Yr47 , Yr35 , Yr36 , Yrxy1 , Yr59 , Yr52 and YrYL . In total, seven QTL (positioned on chromosomes 1D, 2A, 3A, 3D, 5D, 7B and 7D) did not collocate with previously reported genes or QTL, indicating the presence of promising novel resistance factors. Overall, the Vavilov ersity panel provides a rich source of new alleles which could be used to broaden the genetic bases of YR resistance in modern wheat varieties.
Publisher: Wiley
Date: 04-10-2007
Publisher: Springer Science and Business Media LLC
Date: 2005
DOI: 10.1071/AP05068
Publisher: Informa UK Limited
Date: 05-01-2020
Publisher: Wiley
Date: 06-1989
Publisher: Wiley
Date: 03-11-2010
Publisher: Naturalis Biodiversity Center
Date: 23-12-2015
Publisher: Springer Science and Business Media LLC
Date: 04-10-2017
DOI: 10.1007/S00122-017-2990-5
Abstract: Thirteen potentially new leaf rust resistance loci were identified in a Vavilov wheat ersity panel. We demonstrated the potential of allele stacking to strengthen resistance against this important pathogen. Leaf rust (LR) caused by Puccinia triticina is an important disease of wheat (Triticum aestivum L.), and the deployment of genetically resistant cultivars is the most viable strategy to minimise yield losses. In this study, we evaluated a ersity panel of 295 bread wheat accessions from the N. I. Vavilov Institute of Plant Genetic Resources (St Petersburg, Russia) for LR resistance and performed genome-wide association studies (GWAS) using 10,748 polymorphic DArT-seq markers. The ersity panel was evaluated at seedling and adult plant growth stages using three P. triticina pathotypes prevalent in Australia. GWAS was applied to 11 phenotypic data sets which identified a total of 52 significant marker-trait associations representing 31 quantitative trait loci (QTL). Among them, 29 QTL were associated with adult plant resistance (APR). Of the 31 QTL, 13 were considered potentially new loci, whereas 4 co-located with previously catalogued Lr genes and 14 aligned to regions reported in other GWAS and genomic prediction studies. One seedling LR resistance QTL located on chromosome 3A showed pronounced levels of linkage disequilibrium among markers (r
Publisher: Elsevier BV
Date: 08-2006
DOI: 10.1016/J.MYCRES.2006.03.008
Abstract: Fusarium wilt of banana is a potentially devastating disease throughout the world. Options for control of the causal organism, Fusarium oxysporum f.sp. cubense (Foc) are limited. Suppressive soil sites have previously been identified where, despite the presence of Foc, Fusarium wilt does not develop. In order to understand some aspects of this disease suppression, endophytic Fusarium oxysporum isolates were obtained from banana roots. These isolates were genetically characterized and compared with an isolate of Fusarium oxysporum previously identified as being capable of suppressing Fusarium wilt of banana in glasshouse trials. Three additional isolates were selected for glasshouse trials to assess suppression of Fusarium wilt in two different cultivars of banana, Cavendish and Lady Finger. One isolate (BRIP 29089) was identified as a potential biocontrol organism, reducing the disease severity of Fusarium wilt in Lady Finger and Cavendish cultivars. Interestingly, one isolate (BRIP 45952) increased Fusarium wilt disease severity on Cavendish. The implications of an isolate of Fusarium oxysporum, non-pathogenic on banana, increasing disease severity and the potential role of non-pathogenic isolates of Fusarium oxysporum in disease complexes are discussed.
Publisher: CSIRO Publishing
Date: 2000
DOI: 10.1071/AR99172
Abstract: Genetic variation among Australian isolates of the fungus Fusarium oxysporum f. sp. cubense (Foc), which causes Fusarium wilt in banana, was examined using DNA lification fingerprinting (DAF). Ninety-four isolates which represented Races 1, 2, 3, and 4, and vegetative compatibility groups (VCGs) 0120, 0124, 0125, 0128, 0129, 01211, 01213/16, and 01220 were analysed. The genetic relatedness among isolates within each VCG, and between the 8 different VCGs of Foc present in Australia was determined. The DNA fingerprint patterns were VCG-specific, with each VCG representing a unique genotype. The genetic similarity among isolates within each VCG ranged from 97% to 100%. Among the different VCGs of Foc, 3 major clusters were distinguished which corresponded with race. All Race 1 and 2 isolates (VCGs 0124, 0125, 0128, and 01220) were closely related and clustered together, the Race 3 isolates from Heliconia clustered separately, and all Race 4 isolates (VCGs 0120, 0129, 01211, and 01213/16) clustered together. Fifteen isolates from Alstonville, NSW, were characterised because although they were classified as Race 2 based on their recovery from cooking banana cultivars, they belonged in VCG 0124, which had previously contained only Race 1 isolates. The occurrence of more than one race within a VCG means that vegetative compatibility grouping cannot be used to assign pathotype to pathogenic race as previously thought. It was possible to distinguish the Race 1 and Race 2 isolates within VCG 0124 using DNA fingerprinting, as each race produced a unique DNA fingerprint pattern. Among the Australian isolates, DNA fingerprinting analysis identified 9 different VCGs and genotypes of Foc.
Publisher: International Society for Horticultural Science (ISHS)
Date: 03-2016
Publisher: International Society for Horticultural Science (ISHS)
Date: 03-2016
Publisher: Springer Science and Business Media LLC
Date: 09-02-2012
Publisher: International Society for Horticultural Science (ISHS)
Date: 06-2018
Publisher: Elsevier BV
Date: 11-2010
Publisher: Scientific Societies
Date: 02-2008
Abstract: Muskmelon (Cucumis melo L.) is one of the most important vegetable crops in Oman. In the fall of 2004, sudden wilt was observed in muskmelon grown in a field at Sultan Qaboos University, Muscat. The disease was characterized by rapid collapse of vines and muskmelon plants at the fruit production to maturation stage, associated with brown-to-dark brown rotted primary and secondary roots. The disease resulted in death of more than 85% of muskmelon plants in that field. On potato dextrose agar (PDA), with published methods (1), Pythium spp. were consistently isolated from crowns and roots of plants showing wilt symptoms. Further identification of five isolates of Pythium with sequences of the internal transcribed spacer (ITS) of the ribosomal DNA (1) using ITS1 and ITS4 primers produced a nucleotide sequence 806 bp long, which was identical among all isolates. Comparison with sequences deposited at the National Center for Biotechnology Information revealed 100% nucleotide similarity to a previously published sequence (Accession No. DQ381808) of isolate P091 of P. splendens from cucumber from Oman, for which identification has also been confirmed by morphological characteristics. The sequence of one isolate of P. splendens (P222) was assigned GenBank Accession No. EF546436 and deposited at CBS under Accession No. CBS121855. In pathogenicity tests conducted in a greenhouse, P. splendens induced d ing-off symptoms on 7-day-old muskmelon seedlings and also reproduced the same wilt symptoms observed in the field when 2-month-old muskmelon plants were inoculated with 3-day-old P. splendens grown in PDA. To our knowledge, this is the first report of association of P. splendens with wilt of muskmelon in Oman. Reference: (1) A. M. Al-Sa'di et al. Plant Pathol. 56:140, 2007.
Publisher: Oxford University Press (OUP)
Date: 10-07-2012
Abstract: The LATERAL ORGAN BOUNDARIES (LOB) DOMAIN (LBD) gene family encodes plant-specific transcriptional regulators functioning in organ development. In a screen of Arabidopsis (Arabidopsis thaliana) sequence-indexed transferred DNA insertion mutants, we found disruption of the LOB DOMAIN-CONTAINING PROTEIN20 (LBD20) gene led to increased resistance to the root-infecting vascular wilt pathogen Fusarium oxysporum. In wild-type plants, LBD20 transcripts were barely detectable in leaves but abundant in roots, where they were further induced after F. oxysporum inoculation or methyl jasmonate treatment. Induction of LBD20 expression in roots was abolished in coronatine insensitive1 (coi1) and myc2 (allelic to jasmonate insensitive1) mutants, suggesting LBD20 may function in jasmonate (JA) signaling. Consistent with this, expression of the JA-regulated THIONIN2.1 (Thi2.1) and VEGETATIVE STORAGE PROTEIN2 (VSP2) genes were up-regulated in shoots of lbd20 following treatment of roots with F. oxysporum or methyl jasmonate. However, PLANT DEFENSIN1.2 expression was unaltered, indicating a repressor role for LBD20 in a branch of the JA-signaling pathway. Plants overexpressing LBD20 (LBD20-OX) had reduced Thi2.1 and VSP2 expression. There was a significant correlation between increased LBD20 expression in the LBD20-OX lines with both Thi2.1 and VSP2 repression, and reduced survival following F. oxysporum infection. Chlorosis resulting from application of F. oxysporum culture filtrate was also reduced in lbd20 leaves relative to the wild type. Taken together, LBD20 is a F. oxysporum susceptibility gene that appears to regulate components of JA signaling downstream of COI1 and MYC2 that are required for full elicitation of F. oxysporum- and JA-dependent responses. To our knowledge, this is the first demonstration of a role for a LBD gene family member in either biotic stress or JA signaling.
Publisher: Springer Science and Business Media LLC
Date: 08-12-2011
Publisher: American Society for Horticultural Science
Date: 11-2016
Abstract: Variation in the virulence of Fusarium oxysporum f. sp. fragariae ( Fof ) strains is important when evaluating the resistance of plants to this fungus. Twenty-five isolates of F. oxysporum harvested from strawberry ( Fragaria ×ananassa ) plants growing in Australia were characterized using pathogenicity tests, vegetative compatibility groups (VCGs), and genetic analysis of translation elongation factor 1 alpha (EF-1α). The level of disease varied depending on isolate used, indicating heterogeneous populations of Fof . Two distinct VCGs were identified and corresponded to two of the 10 lineages identified by partial EF-1α. Using a subset of Fof isolates, resistance in eight cultivars ranged from highly resistant to highly susceptible, with some cultivar × isolate interaction. ‘Strawberry Festival’, ‘QHI Sugarbaby’, and ‘DPI Rubygem’ had high levels of resistance across all isolates. Isolates from Western Australia (WA) were genetically distinct from those from Queensland (QLD) and were more virulent to ‘Camarosa’, a major cultivar grown in WA.
Publisher: Wiley
Date: 22-12-2011
Publisher: Scientific Societies
Date: 05-2005
Abstract: Mycosphaerella musicola causes Sigatoka disease of banana and is endemic to Australia. The population genetic structure of M. musicola in Australia was examined by applying single-copy restriction fragment length polymorphism probes to hierarchically s led populations collected along the Australian east coast. The 363 isolates studied were from 16 plantations at 12 sites in four different regions, and comprised 11 populations. These populations displayed moderate levels of gene ersity (H = 0.142 to 0.369) and similar levels of genotypic richness and evenness. Populations were dominated by unique genotypes, but isolates sharing the same genotype (putative clones) were detected. Genotype distribution was highly localized within each population, and the majority of putative clones were detected for isolates s led from different sporodochia in the same lesion or different lesions on a plant. Multilocus gametic disequilibrium tests provided further evidence of a degree of clonality within the populations at the plant scale. A complex pattern of population differentiation was detected for M. musicola in Australia. Populations s led from plantations outside the two major production areas were genetically very different to all other populations. Differentiation was much lower between populations of the two major production areas, despite their geographic separation of over 1,000 km. These results suggest low gene flow at the continental scale due to limited spore dispersal and the movement of infected plant material.
Publisher: Springer Science and Business Media LLC
Date: 2006
DOI: 10.1071/AP06071
Publisher: Wiley
Date: 31-07-2003
Location: United Kingdom of Great Britain and Northern Ireland
Location: United Kingdom of Great Britain and Northern Ireland
Location: United Kingdom of Great Britain and Northern Ireland
Start Date: 08-2020
End Date: 08-2025
Amount: $4,787,259.00
Funder: Australian Research Council
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