Genetic dissection of bacterial brown spot and common bacterial blight resistance in common bean (Phaseolus vulgaris L.)

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University of Guelph


Dry bean (Phaseolus vulgaris L.) is the most important legume crop for direct human consumption, known for being a high plant-based source of protein, starches, and fibres. Bacterial blights are recurring constraints in Ontario and the development of resistant varieties is the most sustainable and cost-effective management strategy. Therefore, the goals of the present study were to evaluate bacterial brown spot (BBS) and common bacterial blight (CBB) resistance levels in Ontario-adapted genotypes, and to identify quantitative trait loci (QTL) associated with resistance. Field and indoor trials were conducted to phenotype plants for disease severity, and mapping populations were developed for QTL identification. Disease severity scores varied among genotypes, with higher scores for CBB compared to BBS. A total of 20 and 18 major QTL were discovered for BBS and CBB, respectively. The identified QTL can potentially be incorporated into molecular breeding programs to improve the selection of resistant genotypes.



Plant Pathology, Genetics, Genomics, QTL Mapping, Breeding