Genome-wide association analysis of resistance to anthracnose in the Middle American Diversity Panel of common bean (Phaseolus vulgaris L.)

Anthracnose (ANTH) caused by Colletotrichum lindemuthianum is a major disease of common bean (Phaseolus vulgaris L.). The genetic basis of ANTH resistance in the Middle American Diversity Panel (MDP) is unknown. The objectives of this study were to identify (1) Middle American accessions resistant to races 7, 19, 51, 63, 167, and 1085 of C. lindemuthianum and (ii) genomic regions and positional candidate genes associated with resistance to these races. The MDP composed of 240 Middle American accessions was evaluated for resistance to races 7, 19, 51, 63, 167, and 1085. The MDP was genotyped with 211,763 single nucleotide polymorphisms (SNPs), and mixed linear model analysis was conducted to identify genomic regions associated with resistance to the six races. Seven accessions were highly resistant to all six races, and these can be used as sources of resistance to improve specific market classes in the Middle American gene pool. The genomic region (385,894 bp) on chromosome Pv04 was significantly associated with resistance to race 167. Genomic regions on Pv02 (41,570,325 bp), Pv07 (24,122,343 bp), and Pv11 (51,707,917 bp) were significantly associated with resistance to race 19. Disease resistance (R) genes with the nucleotide binding-APAF resistance protein and CED-4 domain were identified as positional candidate genes on Pv04 and Pv11. There were no SNPs significantly associated with resistance to races 7, 51, 63, and 1085. Pyramiding the identified genomic regions on Pv04, Pv07, and Pv11 could provide durable ANTH resistance in Middle American varieties for races 19 and 167.