RAPD markers linked to a block of genes conferring rust resistance to the common bean

Abstract Rust, caused by the fungus Uromyces appendiculatus , may cause a significant loss to common bean ( Phaseolus vulgaris L.) yield.RAPD markers tightly linked to the resistance genes may be used in breeding programs to aid the development of rust-resistant b eancultivars. In this sense, the objective of the present work was to identify RAPD markers linked to a rust resistance gene block present inthe cultivar Ouro Negro. Two hundred and fourteen F 2 individuals from a cross between the resistant cultivar Ouro Negro and thesusceptible cultivar US Pinto 111 were inoculated with a mixture of eight races of U. appendiculatus . The segregation ratio obtainedsuggested that resistance is monogenic and dominant. Bulked segregant analysis was used in conjunction with the RAPD technique tosearch for markers linked to rust resistance genes. Two molecular markers flanking the rust resistance gene block were identifi ed, one at5.8 ± 1.6 cM (OX11 630 ) and the other at 7.7 ± 1.7 cM (OF10