Genome-wide association analysis for weevil resistance in the Andean gene pool of common bean

The common bean weevil [Acanthoscelides obtectus (Say)] (AO) is the most important post-harvest pest of common bean (Phaseolus vulgaris L.) worldwide. Identifying sources of AO resistance and resistance loci is critical to developing resistant varieties. The Andean Diversity Panel (ADP) comprised of landraces, breeding lines and varieties from various countries and breeding programs is a major genetic and breeding resource of common bean. There are no previous efforts to understand the extent of genetic variability in the ADP for AO resistance and genetic basis of that possible resistance. The objectives of this study were to: (i) identify Andean genotypes resistant to AO, and (ii) identify genomic regions associated with AO resistance. The ADP (n = 476) was evaluated for resistance to AO. Number of perforations on the seed and percentage of damaged seed were recorded and used as metrics for AO resistance. The ADP was genotyped with 24,772 SNPs and genome-wide association analysis was conducted. Significant variability for AO resistance was observed in the ADP. A total of 15 accessions in variable market classes showed AO resistance. These 15 accessions can be used as sources of resistance to enhance AO resistance in specific market classes of common bean. Genomic regions on Pv03 and Pv07 with coefficient of determination (R2) of 14.2% and 17.1%, respectively, were significantly associated with AO resistance. These two identified genomic regions if validated can be used in combination with the Arcelin, Phytohemaglutinin and Apha-amylase (APA) locus on Pv04 to offer durable resistance to AO.