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

ABSTRACT

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.

Keywords:

• common bean
• anthracnose
• Co-genes
• marker assisted selection