Effect of gamma-irradiation on the hereditary variability of kidney bean (Phaseolus Vulgaris L.) cultivars

Seeds of the Cvs Dobruzhanski 2, Dobruzhanski 3, Ruse 3, Biser, Kolarovets 27, Dunav 1 and Sataya 425 (black) were gamma-irradiated with 8, 12, 16 krad doses in 1979. Field germination, survival rate, chlorophyll mutations, and some morphological criteria were studied in M1. It was found that 16 krad irradiation dose reduced field germination by 18.3-31.4%. Growth and development were retarded and plant fertility was lowered. A stimulating effect on pod number per plant was observed only in the indeterminated cultivars. Hundred-sixty-four plants were selected for their morphological characters in M2. Their progenies in M3 were checked up. Valuable for bean breeding early, large-seeded and with coloured seed coat mutants were found. The mutant lines M-634/2, M-636/4 and M-637/12 were recommended as initial forms for intercultivar hybridization. They were characterized by white seeds, upright determinate bush and high situated pods, which made them suitable for mechanical harvesting