ダイズにおける成熟異常個体の発生実態ならびにその識別規準について

抄録

In order to elucidate the occurrence of delayed stem maturation (DSM) plants, we investigated the frequence of DSM plants at Fukuoka, Kyushu, with early soybean varieties grown at four different regions (Hokkaido, Tohoku, Kanto-Tosan and Kyushu) from the north to the south in Japan. The moisture percentages and chlorophyll contents in stem and pod wall were also examined almost the harvesting maturity (95% pods brown) to evaluate the usefullness of green stem color loss as a visual indicator of DSM plant. 1. The frequence of occurrence of DSM plants decreased in the order of Hokkaido (the most northern, cool area), Kanto-Tosan, Tohoku and Kyushu (the most southern, warm area), but DSM plants appeared slightly even in Kyushu varieties. There were higher and lower frequency varieties with DSM plant regardless of the native place of variety. 2. Green color of stem and pod disappeared at about 55 percent of moisture from them. This indicated that the change of chlorophyll content in stem and pod wall was correlated with the change of their moisture content. Therefore, by visually comparing the degree of green stem color change, we can easily distinguish the difference between normal matured and DSM plants. 3. The number of pod and seed weight of DSM plant were similar to those of normal matured plant regardless of the native place of variety, indicating that the occurrence of the DSM plant was not related to yield characters (number of pod, seed weight).