東北地域の野生大豆 (ツルマメ) の収集 1) 秋田県内雄物川流域河川の収集

Wild soybean (Glycine soja) is a very important gene source for soybean breeding, because it has many useful characteristics such as high protein content, variability of protein and lipid composition and resistance or tolerance to insect pest or disease. And it also has high yielding ability such as many branches and pods. Although wild soybean can be seen widely in Japan, no collection has been done so far except in the Chubu district. This report is the result of wild soybean collecting around the Tohoku district in Japan, mainly along the Omono River in Akita prefecture (Fig. 2). We collected 148 wild soybeans along the Omono River, near 7 main branch rivers and 49 along sub-branch rivers flowing into the Omono River from September 26 to October 15, 1993. The number of collecting places was 100 (Table 1 and Table 2). We collected soybeans with larger and smaller leaves, and with late and early maturity at the same collecting sites ; The weight of 100 seeds of wild soybeans collected varied from 1.2g to 3.7g with the mean value of 2.4g (Fig. 1). After our collecting, we were surprised to know that wild soybeans could be seen everywhere along the Omono River. According to an old farmer, farmers used wild soybeans as feed stuff for livestock in the past. Since river improvement has been done everywhere recently, we are afraid of the disappearance of wild soybeans in the near future