Marker-Assisted Introgression of ‘Co-14’ Gene to Common Bean (Phaseolus vulgaries L.) against Anthracnose (Colletotrichum lindemuthianum)

Abstract

Bean anthracnose is one of the major constraints for the production of common beans in Ethiopia. This study aims to introgress the Co-14 R-gene and creating parental bean cultivars with desirable traits as potential sources of resistance genes in breeding programs. Marker-assisted backcross breeding was used to introgress Co-14 R-gene tagged by CV542014 marker from the donor parent (KT-RWA77) to the recurrent parent (KT-IBMV4). Progenies in each generation were selected using sequence tagged site marker (CV542014). An experiment was conducted using parental lines, eight BC2F2 isolines, and two released varieties along with three anthracnose races (2047, 1716, and 2342) in the study for phenotypic evaluation of isolines against anthracnose pathogens. The experiment was conducted using a factorial completely randomized design (CRD). The collected data were analyzed using SAS 9.3 software. From genotypic selection, five BC2F2 plants were identified as introgressed lines for anthracnose R-gene from the crosses of KT-IBMV4 and KT-RWA77 with the aid of marker-assisted selection. The result indicated anthracnose R gene (Co-14) was successfully introgressed and traced with the MAS. Again, the analysis of variance (ANOVA) revealed highly significant differences (p < 0.001) among the BC2F2 lines, races, and their interaction. Among the lines, four BC2F2 lines (Plant-3, Plant-5, Plant-9, and Plant-15) showed the lowest mean severity to the three tested races compared with other lines. The BC2F2 lines specifically plant-3 and plant-15 were selected with resistance to anthracnose and Co-14 marker presence. The two BC2F2 lines namely Plant-3 and Plant-15 could be recommended as sources of resistance to anthracnose disease. However, the remaining two BC2F2 lines viz. plant-5 and Plant-9 had resistance reaction to anthracnose disease and were recommended for production after verification where anthracnose disease is widely distributed. Generally, the identified lines would be used as parental materials for the next backcrossing program.