Transfer of Co-1 Gene Locus for Anthracnose Disease Resistance to Fresh Bean (Phaseolus vulgaris L.) Through Hybridization and Molecular Marker-Assisted Selection (MAS)

Abstract

Anthracnose disease, caused by the fungal pathogen Colletotricum lindemuthianum brings about great yield losses in the Blacksea Region of Turkey. The present study is carried out to start the resistance breeding program against anthracnose disease. Five pathogenic strains (2175, 3071, 3303, 3321, 4071) identified previously from Blacksea Region were inoculated on seven foreign anthracnose resistant varieties of fresh bean (MDRK, PM, Kaboon, Widusa, Machinac, Isles and Chinook) as well as on nine breeding lines (T23, TK57, TK1, C31,C28, T7, T26, TK15 and T21) which were developed as Ay?e kad?n type by pure-line selection, a method used for self-pollinated crops. Results indicated that while all the foreign varieties were resistant to these pathogen strains, the pure-lines were all susceptible. Thus foreign varieties and pure-lines were selected as parents to perform 63 combinations of genetic cross with the intention to start anthracnose resistance breeding program, only 18 of which produced seed. Through self fertilization of 360 F1 plants an F2 population of 4365 plants were obtained which were phenotyped for resistance both by inoculation with five pathogen strains as well as using resistance gene (Co-1) linked molecular marker (SEactMcca). Since Ayse Kadin type lines are of Andean origin and Co-1 locus controls resistance against Andean pathogens additional confirmation of Co-1 presence in the resistant F2 lines is of great importance. Marker screening results indicated the presence of Co-1 gene in 6 out of 18 hybrid lines. Confirmation of resistance trait inheritance on 6 F2 lines both by inoculations as well as molecular marker screening for Co-1 gene have given us the opportunity to continue with the backcross studies with high confidence. With this study anthracnose resistance breeding has been initiated in Turkey for the first time and molecular marker assisted selection has been integrated into the breeding program.