Breeding of Common Bean for Resistance to the Physiological Races of Anthracnose Identified in Bulgaria

The resistance of common bean to Colletotrichum lindemuthianum is controlled by a number of race-specific genes. To combine various genes for resistance to anthracnose alternating crossing was performed. The resulting recombinant inbred lines (RILs) are based on the cross DG 2-36 [Red Hawk/TO//AB136/3/Red Hawk/TO//TU/4/DG 98-53]. Breeding for resistance to C. lindemuthianum using several physiological races of anthracnose identified in Bulgaria was performed from F1 to F5 generation. Seven RILs of F6 progeny, possessing more than one specific gene for resistance were selected by RAPD and SCAR markers linked to Co-1 and Co-4 genes. The line DG 2-36-58-3 was determined as the most promising by quality complex of growth habit type, vegetation period, type of seeds, yield and presence of Co-1 and Co-4 genes that confer resistance to 74 out of 78 worldwide recognized anthracnose races. Several common bean varieties with useful breeding traits were investigated as a source of Co-2 specific gene. Cultivar ‘Drezden’ and the new Bulgarian variety ‘Beslet’ carrying of two genes for resistance in the Co-2 locus were determined as promising sources of the gene for the future breeding programs to obtain durable resistance to C. lindemuthianum.