Characterization and Mapping of Anthracnose Resistance Gene in Mesoamerican Common Bean Cultivar Crioulo 159

Abstract

The common bean cultivar Crioulo 159 provides a valuable source of resistance to Colletotrichum lindemuthianum (Sacc. & Magnus) Briosi & Cavara. The objective of this study was to characterize the genetic resistance of Crioulo 159 to C. lindemuthianum races 2, 64, 73, and 2047 through inheritance, allelism testing, and molecular analysis. Populations were obtained from crosses between Crioulo 159 and cultivars possessing anthracnose resistance genes. Inheritance tests performed in the F2 population and F2:3 families derived from Crioulo 159 (R, resistant) × Cornell 49–242 (S, susceptible) and inoculated with races 2047 and 73 showed segregation that fit ratios of 3R:1S and 1RR:2RS:1SS, respectively, indicating the action of a dominant resistance gene in Crioulo 159. The absence of recombination between two identical sets of F2:3 families inoculated with C. lindemuthianum race 2047 and 73, respectively, allowed the conclusion that a single dominant gene controls the resistance of Crioulo 159 to both races. Allelism tests revealed the independence of the gene in Crioulo 159 from those previously characterized for anthracnose resistance genes. Based on the results, we propose naming this newly discovered anthracnose resistance gene in Crioulo 159 as Co‐16. Molecular analyses revealed that sequence‐tagged site marker g2467900/800 is linked in coupling phase at 4.8 cM from the Co‐16 locus on chromosome Pv04. Additionally, molecular markers g2303, BARCPVSSR04561 and BARCPVSSR04570, which are linked to the Co‐34 allele in Ouro Negro, were not linked to the Co‐16 gene in Crioulo 159.