野生ダイズ, 栽培ダイズおよび両種の自然交雑集団の探索, 収集とモニタリング : 秋田県, 茨城県, 高知県, 佐賀県における現地調査から

During 2003 and 2004, a total of 11 individuals of hybrid derivatives between wild and cultivated soybean were found at Akita (1 individual from one site) and Saga (8, 1 and 1 individuals from three sites). The aim of the present survey was to monitor and explore for hybrid derivatives at prefectures of Akita, Ibaraki, Kochi and Saga. In 2005, only one hybrid individual was found in a site at Saga, and no hybrid derivatives were newly found among 39 sites of wild soybean populations, including 14 sites, which were adjacent to soybean field the previous year. These results suggest that 1) pollen flow from soybean to wild soybean is a rare event, and 2) hybrid derivatives are subject to natural selection and obvious hybrid plants are transient in natural habitats