Evidence and Consequence of a Highly Adapted Clonal Haplotype within the Australian Ascochyta rabiei Population
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...[Show more]
|Leo, Audrey E.
|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.
|The research was funded by the Grains Research and Development Cooperation within project UM00052.
|Frontiers Research Foundation
|© 2017 Mehmood, Sambasivam, Kaur, Davidson, Leo, Hobson, Linde, Moore, Brownlie and Ford.
|Frontiers in Plant Science
|haplotype and highly aggressive
|Evidence and Consequence of a Highly Adapted Clonal Haplotype within the Australian Ascochyta rabiei Population
|Imported from ARIES
|060302 - Biogeography and Phylogeography
|060411 - Population, Ecological and Evolutionary Genetics
|Mehmood, Yasir, Griffith University
|Sambasivam, Prabhakaran, Griffith University
|Kaur, Sukhjiwan, Agriculture Victoria
|Davidson, Jenny, South Australian Research and Development Institute
|Leo, Audrey E., Wagga Wagga Agricultural Institute
|Hobson, Kristy, Tamworth Agricultural Institute
|Linde, Celeste, College of Science, ANU
|Moore, Kevin, Tamworth Agricultural Institute
|Brownlie, Jeremy, Griffith University
|Ford, Rebecca, Griffith University
|820499 - Summer Grains and Oilseeds not elsewhere classified
|This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
|Creative Commons Attribution License (CC BY)
|ANU Research Publications
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