Identification of Rafd Markers Linked to a Major Gene for Rust Resistance and Indeterminate Growth Habit Using Bulked Segregant Analysis in a Common Bean Cross

Rust, incited by Uromyces appendiculatus^ is a major disease in common bean {Phaseolus vulgaris L,). Plant growth habit is also an important trait. Indeterminate growth habit was first reported to be controlled by a single dominant gene (Fin) (Lamprecht, 1935). Molecular markers such as isozymes, RFLP, and RAPD, have been used to tag genes for many traits, particularly disease resistance in several crops. Bulked segregant analysis (BSA), developed by Michelmore, et aL(1991), is a method using bulked DNA fi-om the homozygous Fj individuals for rapidly identifying molecular markers linked to a specific gene. This technique has been used to tag disease resistance genes in several crops (Kelly, 1995; Jung et al, 1996; Michelmore et al, 1991). Specific resistance to a pathotype of rust and indeterminate growth habit in the common bean cross PC-50 [resistant (R) to rust and determinate (fin)] X Chichara [susceptible (S) to rust and indeterminate (Fin)] were each reported to be controll^ by single major dominant genes, respectively (Bokosi, 1996). Jung et al. (1996) reported a RAPD marker linked to rust resistance in a recombinant inbred population fi-om the cross PC-50 X XAN-159. Nodari et al. (1993) reported a RFLP marker linked toßn in a dififerent cross. The objective was to identify RAPD markers linked to a nmjor dominant gene for rust resistance and for the Fin gene using BSA in an F2 segregating population fi*om a common bean cross PC-50 X Chichara [Dominican Republic (D.R.)].