Colletotrichum lindemuthianum is a widespread and highly variable pathogen that attacks common bean (Phaseolus vulgaris L.). Identifying new sources of anthracnose resistance in both Andean and Middle American bean types and developing efficient methods for incorporating resistance into elite bean lines is important to breeders worldwide for the development of more durable resistance. Accordingly, a highly diverse panel of 226 Andean beans was screened with eight races of anthracnose to identify and map new sources of resistance using a genome-wide association study (GWAS). Outputs from the GWAS indicated major QTL for resistance on three linkage groups: Pv01, Pv02, and Pv04 and minor QTL on Pv10 and Pv11. Candidate genes associated with the significant SNPs were detected on all five chromosomes. A QTL study with the black bean cultivar ‘Jaguar,’ known to possess resistance to anthracnose race 73, was conducted to determine the basis of the anthracnose resistance commonly used in the MSU breeding program. Resistance to anthracnose was investigated in an F4:6 recombinant inbred line (RIL) population developed from a cross between Jaguar and ‘Puebla 152’ (landrace cultivar known to be susceptible to race 73). Resistance in Jaguar was determined to be conditioned by the single dominant gene Co-1. Using the Illumina BARCBean6K_3 BeadChip, the physical location of the Co-1 locus was mapped between 50.10 and 50.22Mb on chromosome Pv01. The genomic positions of the numerous resistance loci on Pv01, Pv02, Pv04 and Pv11 identified in the Andean panel and RIL population should prove useful for breeding programs interested in improving anthracnose resistance in cultivars using marker assisted selection.
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