人爲突然變異李用에 依한 小麥品種開良 第Ⅱ報, M₂世代의 稈長 및 穗長變異體選拔

Improvement of Wheat Varieties by Induced Mutation Ⅱ. Selection of Culm- and Spike-Mutants in M2 Generation

This experiment was conducted to select useful mutants in two wheat varieties, Youngkwang and Jaekwang, treated with gamma-ray, EMS and EI. 1,685 mutant lines in Youngkwang and 1,249 in Jaekwang were observed on the culm and spike-length compared with their mother variety in M₂ generation. The results obtained were as follows: 1. For induction of desirable mutants such as short culm or long spike length, Youngkwang had greater than Jaekwang. Otherwise mutation frequency treated with both chemical mutagens were higher than with gamma-ray. Many mutant lines were selected near the level of LD-50 in plant growth for each mutagen. 2. A few mutants were decreased above 30% for culm length, while spike length of them were appeared in the same or increased as compared with their mother vaviety. These mutants in M₂ generation were able to select both varieties. 3. 134 mutant lines in Youngkwang and 52 in Jaekwang were selected for short culm mutant, also 137 in Youngkwang and 64 in Jaekwang respectively were selected for long spike mutants.