Plant & Animal Genome V Conference
Town & Country Hotel, San Diego, CA, January 12-16, 1997.
PAG-V: P221 - BREEDING COMMON BEAN FOR RESISTANCE TO FUNGAL DISEASES ASSISTED BY MOLECULAR MARKERS
P221
BREEDING COMMON BEAN FOR RESISTANCE TO FUNGAL DISEASES ASSISTED BY MOLECULAR MARKERS
ALZATE-MARIN, ANA LILIA, Fabio Gelape Faleiro, Geraldo Assis Carvalho, Everaldo Goncalves Barros, Maurilio Alves Moreira
BIOAGRO/UFV, 36571-000 Vicosa, MG, Brasil
Common beans (Phaseolus vulgaris) are particularly susceptible to fungal, bacterial, and viral diseases. We have been conducting a backcross breeding program assisted by molecular markers to create ‘carioca’ type varieties, which are widely planted and accepted in Brazil, resistant to anthracnose, angular leaf spot, rust, and fusariosis. Bulked segregant analysis (BSA) was used to tag genes for resistance to different pathotypes of anthracnose fungus (Colletotrichum lindemuthianum) present in cultivar AB 136 which is resistant to all pathotypes detected in Brazil. Seven RAPD markers have been identified in different crosses involving AB 136. These markers are being used to elucidate the resistance mechanism in this cultivar. Backcross-derived populations involving the ‘carioca’ type cultivar A 285 as recurrent parent have been developed to isolate markers to select resistant plants and to assist the pyramidation of resistance genes from different sources (AB 136, G 2333, Cornell 49-242, a nd TO). A similar approach is being used in the case of angular leaf spot (Phaeoisariopsis griseola) and rust (Uromyces appendiculatus). In the first case, the donor parents are cultivars AND 277, MAR-1, MAR-2, MAR-3, Cornell 49-246, and BAT 332. A RAPD marker linked to a resistance gene to race 158-1 has been identified in the cross AND 277 x A 285. Resistance genes for rust are being introgressed from cultivar Ouro Negro. Isolines from the cross between Ouro Negro and Pinto 111 are being used to isolate resistance genes to the most common pathotypes of the rust fungus occurring in Brazil.