Dissection of Quantitative Blackleg Resistance Reveals Novel Variants of Resistance Gene Rlm9 in Elite Brassica napus .

Autor:	Vollrath P; Department of Plant Breeding, IFZ Research Centre for Biosystems, Land Use and Nutrition, Justus Liebig University Giessen, Giessen, Germany., Chawla HS; Department of Plant Sciences, Crop Development Centre, University of Saskatchewan, Saskatoon, SK, Canada., Alnajar D; Plant Pathology and Crop Protection Division, Department of Crop Sciences, Georg August University of Göttingen, Göttingen, Germany., Gabur I; Department of Plant Breeding, IFZ Research Centre for Biosystems, Land Use and Nutrition, Justus Liebig University Giessen, Giessen, Germany.; Department of Plant Sciences, Faculty of Agriculture, Iasi University of Life Sciences, Iaşi, Romania., Lee H; Department of Plant Breeding, IFZ Research Centre for Biosystems, Land Use and Nutrition, Justus Liebig University Giessen, Giessen, Germany., Weber S; Department of Plant Breeding, IFZ Research Centre for Biosystems, Land Use and Nutrition, Justus Liebig University Giessen, Giessen, Germany., Ehrig L; Department of Plant Breeding, IFZ Research Centre for Biosystems, Land Use and Nutrition, Justus Liebig University Giessen, Giessen, Germany., Koopmann B; Plant Pathology and Crop Protection Division, Department of Crop Sciences, Georg August University of Göttingen, Göttingen, Germany., Snowdon RJ; Department of Plant Breeding, IFZ Research Centre for Biosystems, Land Use and Nutrition, Justus Liebig University Giessen, Giessen, Germany., Obermeier C; Department of Plant Breeding, IFZ Research Centre for Biosystems, Land Use and Nutrition, Justus Liebig University Giessen, Giessen, Germany.
Jazyk:	angličtina
Zdroj:	Frontiers in plant science [Front Plant Sci] 2021 Nov 18; Vol. 12, pp. 749491. Date of Electronic Publication: 2021 Nov 18 (Print Publication: 2021).
DOI:	10.3389/fpls.2021.749491
Abstrakt:	Blackleg is one of the major fungal diseases in oilseed rape/canola worldwide. Most commercial cultivars carry R gene-mediated qualitative resistances that confer a high level of race-specific protection against Leptosphaeria maculans , the causal fungus of blackleg disease. However, monogenic resistances of this kind can potentially be rapidly overcome by mutations in the pathogen's avirulence genes. To counteract pathogen adaptation in this evolutionary arms race, there is a tremendous demand for quantitative background resistance to enhance durability and efficacy of blackleg resistance in oilseed rape. In this study, we characterized genomic regions contributing to quantitative L. maculans resistance by genome-wide association studies in a multiparental mapping population derived from six parental elite varieties exhibiting quantitative resistance, which were all crossed to one common susceptible parental elite variety. Resistance was screened using a fungal isolate with no corresponding avirulence ( AvrLm ) to major R genes present in the parents of the mapping population. Genome-wide association studies revealed eight significantly associated quantitative trait loci (QTL) on chromosomes A07 and A09, with small effects explaining 3-6% of the phenotypic variance. Unexpectedly, the qualitative blackleg resistance gene Rlm9 was found to be located within a resistance-associated haploblock on chromosome A07. Furthermore, long-range sequence data spanning this haploblock revealed high levels of single-nucleotide and structural variants within the Rlm9 coding sequence among the parents of the mapping population. The results suggest that novel variants of Rlm9 could play a previously unknown role in expression of quantitative disease resistance in oilseed rape. Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. (Copyright © 2021 Vollrath, Chawla, Alnajar, Gabur, Lee, Weber, Ehrig, Koopmann, Snowdon and Obermeier.)
Databáze:	MEDLINE
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