감마線을 處理한 大豆 第二世代에서의 突然變異出現率

Mutation Frequency at Seedling Stage M2 Soybean Population Treated with Gamma-Ray

In order to investigate the radiosensitivity in M₁ and frequency of mutants at seedling stage in M₂ population, the air dried seeds of three varieties were irradiated with gamma-ray doses ranged 10~50kR. The fifty percent decrease due to the radiation effects in plant height at 14 days, survival rate at 40 days after seeding, and number of pods per plant at harvest was ranged from 20 to 30 kR and their varietal differences were not found. Frequency of chlorophyll deficient mutation of leaf was 4~7% in M₁ plant bais and 2~4% in M₂ seedling basis within 20~30kR, and significant differences were not, found among the varieties. Frequency of stem color mutation in Korean native line, KAS 552-4 was higher as compared to that of chlorophyll deficient mutation and the rate was 25% and 7% in M₁ and M₂ basis, respectively. The purpose of experiment was to investigate the radiosensitivity in M₁ generation and frequency of mutants at seedling stage in M₂ population of soybean. The air dried seeds of three varieties, Chungbuk-Baik, KAS 552-4 and CB-27 were irradiated with gamma-ray doses of 10, 20, 30, 40 and 50kR. The results obtained are summarized as follows: 1. The fifty percent decrease due to the radiation effects in plant height at 14 days after seeding, survival rate at 40 days after seeding, and number of pods per plant at harvest was ranged from 20 to 30kR and their varietal differences were not found. 2. Mutant types at M₂ seedling stage were classified into chlorophyll deficiency of leaf, stem color at cotyledon stage, rosette type, twin stem, narrow leaf and multi-leaflets types. 3. Frequency of chlorophyll deficient mutation of leaf with xantha, chlorina, chlorotica and maculata type was 4~7% in M₁ plant basis and 2~4% in M₂ seedling basis within 20~30kR, and significant difference were not found among the varieties employed 4. Frequency of green stem color mutation in Korean native line, KAS 552-4 with purple stem at cotyledon stage was higher as compared to that of chlorophyll deficient mutation and the rate was about 25% and 7% in M₁ and M₂ basis, respectively.