Construction and phenotypic observation of a gamma radiation mutant library of common bean cultivar Golden Hook

Common bean(Phaseolus vulgaris L.) is one of the important crops in China and the world.Its various appearances, relative small genome size, short life cycle, and a close phylogentic relationship with soybean, make it an important genetic resource for studying gene function in legume.Aiming to create rich genetic variations, we exposed seeds of Golden Hook to ⁶⁰Co γ radiation at a dosage of 200 Gy, then observed their phenotypes at M₃ generation, and estimated the phenotypic variations of quantitative traits taking 100-seed weight and seed size as representatives.The result showed that, compared with the wild type Golden Hook, mutant lines of Golden Hook displayed a large phenotypic variations in 100-seed weight, seed length, and seed width, with significant differences between selected wild type and line 434 (large seed) or line 601 (small seed).Also, among 3 500 plants in M₃ lines, compared with the wild type Golden Hook, 607 lines varied significantly in flowering and maturing stages, leaf type, plant type, fertility and seed color; 5.5% mutations were in agreement with median 3:1 segregation ratio, indicating those mutations were generally controlled by single gene.Moreover, some phenotypic mutations were confirmed in M₄ generation.Therefore, the obtained genetic mutants could be directly used in common bean breeding, and provided good materials for cloning the casual genes and thereafter studying gene function as well.