γ射线照射27个大豆品种的种子,发现品种间根尖细胞第一次有丝分裂染色体畸变率有明显差异。供试品种可以分为迟钝型和敏感型两组。照射迟钝型和敏感型品种间杂交的 F_2代种子,从染色体畸变的频率分布推测,品种间的差异主要由一个隐性单基因 rs1控制。这个基因是由 Takaki和 Yamashita 发现的,在照射种子或生长中的植株时,控制幼苗生长的受抑程度。 γ ray irradiation of 27 soybean varieties of seeds, found that the root tip cells between the first mitotic chromosome aberration rates were significantly different. Test varieties can be divided into two types of sensitive and sensitive type. The F2 generation hybrids between the insensitive and sensitive cultivars were inferred from the frequency distribution of chromosomal aberrations. The differences among breeds were mainly controlled by a recessive single gene rs1. This gene was discovered by Takaki and Yamashita to control the extent of seedling growth inhibition when irradiated with seed or growing plants.