水稻原胚照射에 있어서 albina突然變異의 分離不足現象

Recessive Deficit of Albina Mutant in the X-ray Irradiation of Rice Pro-embryo

Zygotes or early pro-embryos of rice were X-rayed and segregation of albina mutation was examined. Average segregation ratios in M₂ and M₃ were 0.18 and 0.19 respectively, indicating considerable recessive deficit of mutant from the expected ratio of 0.25. Segregation ratio varied with the mutant lines. Lines with comparatively high segregation ratio numbered 54%, those of highly deficit were 8% and 38% were of intermediate category. The occurrence of albina mutant was affected by the temperature of the room where seeds were germinated. At high temperature segregation ratio was in general higher than at low temperature and certain lines were more sensitive to temperature than others. The ratio of homo dominant and hetero M₂ seed in the M₁ panicle or fixed line vs segregating line in M₂ was examined by sowing the whole M₂ seed of each panicle. There was deviation from the expected ratio of 1 : 2 with the deficit of segregating lines. This tendency was in conformity with the trend in the deficit of recessive albina mutant.