放射線 및 化學藥品處理에 依한 토마토의 雄性不稔系 誘起選拔, 細胞學 및 遺傳學的 硏究

Histological and Genetic Studies on the Male - Sterile Mutants of Tomato Induced by Gamma Radiation and Chemical Mutagens

The object of this experiment was to test the radiosensitivity of the M₁ generation, and to determine the inheritance and morphological characteristics of the male-sterile mutants in tomatoes. The results obtained are as follows: Radiation damage varied with the water content of the seeds. The least damage occurred in the range of 11.34 to 14.29 percent moisture. Four tomato cultivars were gamma irradiated. The cultivar Sekai-ichi was the most sensitive while the other responded similarly to each other. Chemical mutagen treatments caused greater damage to germination, to delayed flowering and to pollen fertility than did radiation. Pollen fertility and seeds per fruit in seedling gamma irradiated plants decreased as the dosage and dose rate increased. Five male-sterile mutants were found. Each was controlled by a single recessive gene. All five male-steriles were nonallelic. Floral sizes of the male-sterile mutants were slightly smaller. Ovule fertility varied, usually being lower than normal type. Male sterility in 109-1ms strain was caused by unbalanced, insufficient nutrients being made available to the pollen-mother cells from the tapetal tissue.