Validation of an SNP marker associated with resistance to common bacterial blight in common bean (Phaseolus vulgaris L.)

Abstract

Marker-assisted selection (MAS) can be an alternative to rapidly select and develop genotypes resistant to common bacterial blight (CBB), a disease that severely impacts common bean production. The aim of this study was to use MAS to evaluate and validate the SNP marker snpPV0039, already identified as linked to the CBB resistance locus SU91, in selection of common bean genotypes that carry the resistance allele. We evaluated a diverse panel of 56 common bean genotypes with different levels of reaction to CBB, as well as 218 F2 plants that had the variety CB911921, resistant to CBB, as a parent. The F2 plants were evaluated regarding their reaction to the pathogen Xanthomonas phaseoli, isolate CNF19 (Xap strain). The snpPV0039 marker amplified the resistance allele associated with QTLSU91 in the main sources of CBB resistance. In addition, a segregation ratio of 1RR:2Rr:1rr was observed, with a recombination frequency of 8.74 cM of the QTLSU91 and a selection efficiency of 96.94%. Based on these results, incorporation of the snpPV0039 marker in the marker-assisted selection routine in the common bean breeding program is strongly recommended.