Development and agronomic performance of common bean lines simultaneously resistant to anthracnose, angular leaf spot and rust

Abstract

The common bean is affected by several pathogens that can cause severe yield losses. Here we report the introgression of resistance genes to anthracnose, angular leaf spot and rust in the ‘carioca‐type’ bean cultivar ‘Rudá’. Initially, four backcross (BC) lines were obtained using ‘TO’, ‘AB 136′, ‘Ouro Negro’ and ‘AND 277’ as donor parents. Molecular fingerprinting was used to select the lines genetically closer to the recurrent parent. The relative genetic distances between ‘Rudá’ and the BC lines varied between 0.0% and 1.99%. The BC lines were intercrossed and molecular markers linked to the resistance genes were used to identify the plants containing the genes of interest. These plants were selfed to obtain the F2, F3 and F4 plants which were selected based on the presence of the molecular markers mentioned and resistance was confirmed in the F4 generation by inoculation. Four F4:7 pyramid lines with all the resistance genes showed resistance spectra equivalent to those of their respective donor parents. Yield tests showed that these lines are as productive as the best ‘carioca‐type’ cultivars.