Caracterização genética da resistência à antracnose do feijoeiro comum cultivar Corinthiano

Abstract

The use of resistant cultivars is one of the most efficient methods to control common bean anthracnose, a fungal disease caused by Colletotrichum lindemuthianum. Thus, it is important a continuing search for new resistance sources. The present study had as objective to characterize Corinthiano Andean cultivar genetic resistance to C. lindemuthianum, 8, 89 and 2047 races by conducting resistance inheritance and allelism tests. In order to obtain F2 populations Corinthiano cultivar was crossed with Michelite, Michigan Dark Red Kidney (MDRK), Cornell 49-242, México 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 cultivars and H1 line. Inheritance test in F2 population from cross between Corinthiano (R) x Cornell 49-242 (S) cultivars, inoculated with race 2047, revealed a segregation fitted 3R:1S ratio, indicating the presence of a dominant gene in Corinthiano cultivar. Allelism tests demonstrated that this gene is independent from previous characterized ones, Co-1, Co-14, Co-3, Co-33, Co-4, Co-42, Co-6, Co-7, Co-10, Co-11, Co-12, Co- 13 and the gene present in the Pitanga cultivar. It was concluded that Corinthiano possesses a new Andean gene of resistance against anthracnose, and authors propose this one should be named Co-15.