IDENTIFICATION OF DOMINANT MALE STERILE MUTANTS IN RICE ( Oryza sativa L.)

Genetic male sterile mutants 1783 and 1789 were selected from US variety Orion and Kaybonnet seeds treated by gamma irradiation. Investigation of fertility characterization of pollen and spikelets of these mutants were made by progeny tests in 1783 M 7 and 1789 M 6 generations. The results showed that genetic male sterile mutants 1783 and 1789 with the fertility segregating of 1 sterile:1 fertile were controlled by a single dominant gene. The pollen staining of mutants characterized partial sterility. Open pollinated seed set was about 30% and bagged seed set was only 0 3%～3 5%. It is concluded that dominant genetic male sterile is a useful tool in improvement of population for rice breeding.