Identification of mutants for abnormal pollen development in rice

To gain a comprehensive understanding of the genetic regulation of male gametogenesis, we screened and identified mutants for abnormal pollen development in rice (Oryza sativa L.). We gamma-irradiated spikelets of a japonica rice cultivar, Taichung 65, just before and after anthesis. Among 1,000 M-2 lines, 24 lines were identified as mutants for pollen sterility. Progeny tests in M-3 demonstrated that pollen sterility in 12 lines was controlled by single recessive genes, designated spsl-sps12 (sporophytic pollen sterility). In the remaining 12 lines, pollen semi-sterility was under the control of gametophytic genes, designated gps1-gps12 (gametophytic pollen sterility). Linkage analysis revealed that sps6, sps9, and sps12 were mapped on chromosomes 3, 9, and 7, respectively.