油菜 人爲 突然變異에 의한 M₂世代의 量的形質 變異體選拔

Selection of mutants expressed quantitatively in M₂ generation of rapeseed

This experiment was conducted to select useful mutants in three rapeseed varieties, Naehan, Youngsan, and Mokpo-59, treated with gamma-ray 30 KR. One hundred and ninety seven mutant lines in Naehan, 131 in Youngsan and 256 in Mokpo-59 were evaluated for flowering date, plant height and other characters compared with their mother varieties in M₂ generation. The results obtained are summarized as follows : More than 94% of the mutants matured earlier for flowering date and 75% were shorter in plant height while ear length appeared the same or increased as compared with their mother varieties. These mutants in the M₂ generation were able to be selected. Two mutant lines in Naehan and Youngsan, and three mutant lines in Mokpo-59 were selected for early flowering date, shorter plant height and longer ear length, respectively. Mutants had more branches above 78%, 27% for the first and the second branch, respectively. Mutants with more pods per ear were able to be selected in the mutant populations as compared with thir mother varieties. Four mutant lines in Naehan and Youngsan and three in Mokpo-59 with more branches and pods were selected, respectively.