Abstract: Sterile plants were screened from 8327 soybean landraces and 414 hybrid populations during 1998-2003, and eleven and six sterile lines were identified and evaluated respectively. Ten of the eleven sterile lines obtained from different landraces might be natural mutants according to their morphological and agronomical performances similar to their corresponding parents. Among the 17 sterile lines, 13 lines performed completely male sterile and four lines were male partially sterile, and the female fertility of these lines could also be divided into fertile, partially sterile and completely sterile according to the results of parallel crossing and natural outcrossing rate of sterile lines, therefore, all the sterile lines were grouped into six male and female performance types. Among them, seven lines belonged to the male-sterile and female-fertile (MS-FF) type (including NJS-3H, NJS-4H, NJS-8H with good outcrossing ability); two lines (NJS-2H, NJS-12H) were male sterile, female partially sterile (MS-FPS); two lines(NJS-9, NJS-11H) were male partially sterile, female fertile(MPS-FF); three lines NJS-18H, NJS-7H, NJS-10H were male-sterile and female-sterile (MS-FS), both male and female partially sterile(MPS-FPS), and male partially sterile and female sterile(MPS-FS) types, respectively; and other three lines(NJS-17H、NJS-20H、NJS-22H) were male sterile but female fertility uncertain yet. The results of genetic analyses showed that the sterility of 17 lines was controlled by nuclear gene(s). Some sterile lines, including NJS-8H (MS-FF type controlled by one dominant gene), NJS-2H and NJS-12 (MS-FPS new type by one recessive gene), NJS-9 (MPS-FF type by two recessive genes), NJS-7H (MPS-FPS type by two recessive genes), and NJS-10H (MPS-FS type with abnormal flower structure and leaf shape), were new sterility types in soybean, and other lines appeared one recessive gene inheritance. The mutation rate of sterility was estimated as 0~1.87×10-4 from five cultivars with large population size. The present study indicates that there exists certain amount of natural variation and mutants in sterility which are feasible to be obtained through natural variation selection and could be used as elite sources for further research on developmental and reproductive biology as well as in breeding programs of soybeans.

Key words: Soybean, Nuclear male sterility (NMS), Male and female fertility, Inheritance