INTROGRESSION OF ANGULAR LEAF SPOT RESISTANCE GENES IN COMMON BEAN ISOLINES

摘要

In Brazil, until the end of the 1980's, angular leaf spot caused by Phaeoisariopsis griseola was considered a disease of minor economical impact. According to VIEIRA (1998), the disease was not seen as an important one because it only occurred at theend of the culture cycle, with little effect on productivity. However, in the last years, angular leaf spot has been causing great losses, with severe defoliation in some cultivars. The existence of physiological races and the constant evolution of the pathogen demand a permanent search for new resistance sources. The pyramiding or association of resistance genes in the same cultivar has been proposed as a strategy to achieve long-term and broad spectrum resistance (KELLY et al., 2003). In the BIOAGRO/UFV Bean Breeding Program, carioca type isolines have been developed containing the following genes: Ur-ON and Co-10, which confer resistance to rust and anthracnose, respectively, from the Ouro Negro; Co-4 and Co-6, which confer resistance to anthracnose, from the TO and AB 136, respectively; Phg-1, which confer resistance to angular leaf spot, from AND 277. RAGAGNIN et al. (2005) intercrossed these materials pyramiding these genes into four isolines which were named Ruda "R".