Mapping of an andean gene for anthracnose resistance (Co-13) in common bean (Phaseolus vulgaris L.) Jalo Listras Pretas landrace

摘要

The common bean (Phaseolus vulgaris L.) andean Jalo Listras Pretas (JLP) landrace is an important source of resistance to anthracnose, which is a widespread disease caused by Colletotrichum lindemuthianum fungus. This common bean landrace carries Co-13 gene, one of the nine ones identified andean anthracnose resistance genes. The present study set out to identify molecular markers associated with Co-13 by evaluating the segregation patterns of 65 molecular markers, in a F2 population derived from a cross between JLP (resistant to race 73 of C. lindemuthianum) and Cornell 49-242 (susceptible to race 73 of C. lindemuthianum) cultivars. Bulked segregant analysis was performed to identify which of these molecular markers was linked to Co-13 in JLP. Among the analyzed molecular markers, OV20680 marker displayed a heteromorphic band of 680 bp linked to Co-13 resistant gene in coupling phase. Genotyping of the OV20680 marker in F2 population revealed a recombination of 1.7%, indicating a tight linkage between the OV20680 marker and disease resistance gene (Co-13). In the recombinant inbred population BAT93/Jalo EEP558, OV20680 segregated according to a 1:1 ratio and mapped on linkage group Pv03 at a distance of 1.8 cM from the Co-13 locus. Jalo Listras Pretas has shown to be an important source of resistance to anthracnose, possessing a new gene that should be valuable in breeding for anthracnose resistance in common bean. Identifying molecular markers linked to andean resistance genes may facilitate the development of cultivars with broad-based resistance to anthracnose by streamlining the process of combining andean and mesoamerican resistance genes.