Genetic Characterization and Mapping of Anthracnose Resistance of Common Bean Landrace Cultivar Corinthiano

Abstract

ABSTRACT The objectives of this study were to characterize the genetic resistance in the Andean common bean ( Phaseolus vulgaris L.) cultivar Corinthiano to races 8, 65, 89, and 2047 of Colletotrichum lindemuthianum (Sacc. & Magnus) Briosi & Cavara through inheritance and allelism tests and to map the source of resistance. Corinthiano was crossed with cultivars Michelite, Michigan Dark Red Kidney (MDRK), Cornell 49‐242, Mexico 222, PI 207262, TO, TU, AB 136, G 2333, Jalo Listras Pretas (JLP), Jalo Vermelho (JV), BAT 93, Ouro Negro, AND 277, Pitanga, SEL 1308, H1 line, and Crioulo 159 to generate F 2 populations. Inheritance tests conducted in F 2 population and F 2:3 families from the cross Corinthiano (resistant [ R ]) × Cornell 49‐242 (susceptible [ S ]) inoculated with race 2047 showed segregation that fit ratios of 3 R :1 S and 1 RR :2 Rr :1 rr , respectively, indicating the action of a dominant resistance gene in Corinthiano. Allelism tests demonstrated that the gene in Corinthiano is independent from those previously characterized genes: Co‐1 , Co‐1 4 , Co‐2 , Co‐3 , Co‐3 3 , Co‐3 4 , Co‐3 5 , Co‐4 , Co‐5 , Co‐5 2 , Co‐4 2 , Co‐6 , Co‐11 , Co‐12 , Co‐13 , Co‐14 , and Co‐16 that are present in the genotypes tested. The symbol Co‐15 was assigned to this newly discovered anthracnose resistance gene in Corinthiano. Molecular analyses revealed that the sequence‐tagged site (STS) marker g2685 is linked in coupling phase at 5.6 cM from the Co‐15 locus. This marker was also polymorphic in the mapping population BAT 93/Jalo EEP 558, which confirmed the location of this marker and the Co‐15 gene on Pv04. Corinthiano 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.