School of Agriculture, Food and Ecosystem Sciences - Research Publications
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ItemNo Preview AvailableSustainable development implications of human wildlife conflict: an analysis of subsistence farmers in Bhutan(TAYLOR & FRANCIS INC, 2023-07-04)
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ItemThe role of social license in conservation(WILEY, 2018-04)
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ItemNeed for empirical evidence to support use of social license in conservation: reply to Garnett et al.(WILEY, 2018-06)Article impact statement: Understanding the role of social license informs managers and policy makers of community support and acceptance of conservation actions.
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ItemDefence gene expression profiling to Ascochyta rabiei aggressiveness in chickpea(SPRINGER, 2016-07)Significant differences in defence pathway-related gene expression were observed among chickpea cultivars following A. rabiei infection. Differential gene expression is indicative of diverse resistances, a theoretical tool for selective breeding. A high number of Ascochyta rabiei pathotypes infecting chickpea in Australia has severely hampered efforts towards breeding for sustained quantitative resistance in chickpea. Breeding for sustained resistance will be aided by detailed knowledge of defence responses to isolates with different aggressiveness. As an initial step, the conserved and differential expressions of a suit of previously characterised genes known to be involved in fungal defence mechanisms were assessed among resistant and susceptible host genotypes following inoculation with high or low aggressive A. rabiei isolates. Using quantitative Real-Time PCR (qRT-PCR), 15 defence-related genes, normalised with two reference genes, were temporally differentially expressed (P < 0.005) as early as 2 h post inoculation of Genesis090 (resistant) or Kaniva (susceptible). The highly aggressive isolate, 09KAL09, induced vastly different expression profiles of eight key defence-related genes among resistant and susceptible genotypes. Six of these same genes were differentially expressed among ten host genotypes, inclusive of the best resistance sources within the Australian chickpea breeding program, indicating potential use for discrimination and selection of resistance "type" in future breeding pursuits.
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ItemDevelopment of a multiplex PCR diagnostic assay for the detection of Stagonosporopsis species associated with ray blight of Asteraceae(SPRINGER, 2016-11)Ray blight, a destructive disease of Asteraceae worldwide, is caused by three morphologically similar but phylogenetically distinct species; Stagonosporopsis chrysanthemi, S. inoxydabilis and S. tanaceti. Stagonosporopsis chrysanthemi has been reported as a specific pathogen of chrysanthemum while S. inoxydabilis has been found associated with various Asteraceae. Stagonosporopsis tanaceti has only been reported in Australia, causing substantial crop loss on pyrethrum. All three species were shown to infect and cause disease on in vitro grown pyrethrum plants, hence, S. chrysanthemi and S. inoxydabilis may pose a significant biosecurity threat to the Australian pyrethrum industry. All these Stagonosporopsis species are also Level 2 quarantine pathogens in Europe. Rapid and accurate detection and differentiation of these species is a priority for ray blight management in Australia and in Europe. Accordingly, three species-specific PCR-based assays, targeted to the intergenic spacer of the nuclear ribosomal DNA, were developed. The specificity of each assay was confirmed against 21 Stagonosporopsis spp. as well as 14 pathogenic and saprophytic fungal species commonly found in association with pyrethrum in Australia. The primers were highly sensitive and specific to the target species, detecting down to 4 fg of genomic DNA. These primers were further used in a multiplex PCR to differentiate the presence of the three Stagonosporopsis spp. based on variable sized amplicons in a single reaction.
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ItemPathogenic variation and virulence related responses of Ascochyta lentis on lentil(SPRINGER, 2017-02)Ascochyta blight of lentil (Lens culinaris ssp. culinaris) is caused by Ascochyta lentis. The disease causes severe damage to all aerial parts of the plant and may lead to total crop loss during extremely severe epidemics. To identify qualitative differences in resistance within Australian lentil crops, variation in virulence was examined among 17 isolates of A. lentis on six differential lentil genotypes (ILL7537, ILL5588 (cv. Northfield), ILL6002, ILL5722 (cv. Digger), ILL481 (cv. Indianhead) and CIPA203 (cv. Nipper)). Six distinct virulence patterns were identified, with Pathotype I (AL4) being highly virulent, causing disease on all genotypes except ILL7537 and pathotype VI (Kewell) exhibiting low virulence on all genotypes. Histopathology studies were carried out to further understand interaction differences between isolate-host combinations and add to the knowledge of possible resistance mechanisms underlying lentil’s defence to the pathogen. The infection process was compared between lentil genotypes with different levels of resistance and isolates with different levels of virulence. Microscopic and biochemical differences were observed between compatible and incompatible interactions, which were related to time-after-inoculation, with slower responses noted in susceptible lentil genotypes. Relatively fast release of reactive oxygen species (ROS) and a subsequent hypersensitive response (HR) was central to initial defence at the point of penetration in the most resistant lentil genotypes.
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ItemThe detection of QTLs in barley associated with endosperm hardness, grain density, grain size and malting quality using rapid phenotyping tools(SPRINGER, 2013-10)Using a barley mapping population, 'Vlamingh' × 'Buloke' (V × B), whole grain analyses were undertaken for physical seed traits and malting quality. Grain density and size were predicted by digital image analysis (DIA), while malt extract and protein content were predicted using near infrared (NIR) analysis. Validation of DIA and NIR algorithms confirmed that data for QTL analysis was highly correlated (R (2) > 0.82), with high RPD values (the ratio of the standard error of prediction to the standard deviation, 2.31-9.06). Endosperm hardness was measured on this mapping population using the single kernel characterisation system. Grain density and endosperm hardness were significantly inter-correlated in all three environments (r > 0.22, P < 0.001); however, other grain components were found to interact with the traits. QTL for these traits were also found on different genomic regions, for example, grain density QTLs were found on chromosomes 2H and 6H, whereas endosperm hardness QTLs were found on 1H, 5H, and 7H. In this study, the majority of the genomic regions associated with grain texture were also coincident with QTLs for grain size, yield, flowering date and/or plant development genes. This study highlights the complexity of genomic regions associated with the variation of endosperm hardness and grain density, and their relationships with grain size traits, agronomic-related traits, and plant development loci.
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ItemWhat do you mean by values? Integration of social with biophysical knowledge in the development of a landscape decision support system(ELSEVIER SCI LTD, 2021-10-01)Environmental decision-making is recognised as requiring integration of biophysical and social knowledge, but integration of knowledges based in different epistemic assumptions is challenging. We used an action research approach to observe integration in the development of a landscape decision support system (DSS) for forest and fire management in Victoria, Australia. We found two different knowledge integration processes, conceptually-driven to shape the structure of the DSS and technically-driven through modelling. Project framing dominated by biophysical sciences and technically-driven integration presented a barrier to many potential social science contributions that could connect a DSS with the surrounding social and decision contexts. Nonetheless, some conceptually-driven integration occurred when social researchers contributed their analysis of values of the public to the DSS design. The need for this integration emerged through initial conflict over disciplinary understandings of ‘value’. While initially uncomfortable, this opened the way to differentiate knowledge related to the term and to negotiate some conceptual synthesis and an agreed multidisciplinary list of values to structure the DSS. Technically-driven integration occurred through incorporation of social and biophysical metrics in model software. Our research highlights that bridging concepts such as values and related frameworks act as boundary objects that help in overcoming barriers to integration between social and biophysical knowledge. Integration is itself a potential boundary object and early discussions to differentiate and clarify how the term is understood can help in designing interdisciplinary processes. Critically, projects need adequate time for interdisciplinary differentiation, tolerance amongst the team for uncomfortable conversations, and leadership that fosters interdisciplinary interactions to achieve a high degree of knowledge integration.
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ItemEvidence and Consequence of a Highly Adapted Clonal Haplotype within the Australian Ascochyta rabiei Population.(Frontiers Media SA, 2017)The Australian Ascochyta rabiei (Pass.) Labr. (syn. Phoma rabiei) population has low genotypic diversity with only one mating type detected to date, potentially precluding substantial evolution through recombination. However, a large diversity in aggressiveness exists. In an effort to better understand the risk from selective adaptation to currently used resistance sources and chemical control strategies, the population was examined in detail. For this, a total of 598 isolates were quasi-hierarchically sampled between 2013 and 2015 across all major Australian chickpea growing regions and commonly grown host genotypes. Although a large number of haplotypes were identified (66) through short sequence repeat (SSR) genotyping, overall low gene diversity (Hexp = 0.066) and genotypic diversity (D = 0.57) was detected. Almost 70% of the isolates assessed were of a single dominant haplotype (ARH01). Disease screening on a differential host set, including three commonly deployed resistance sources, revealed distinct aggressiveness among the isolates, with 17% of all isolates identified as highly aggressive. Almost 75% of these were of the ARH01 haplotype. A similar pattern was observed at the host level, with 46% of all isolates collected from the commonly grown host genotype Genesis090 (classified as "resistant" during the term of collection) identified as highly aggressive. Of these, 63% belonged to the ARH01 haplotype. In conclusion, the ARH01 haplotype represents a significant risk to the Australian chickpea industry, being not only widely adapted to the diverse agro-geographical environments of the Australian chickpea growing regions, but also containing a disproportionately large number of aggressive isolates, indicating fitness to survive and replicate on the best resistance sources in the Australian germplasm.