Three panicle morphogenesis mutants were identified from a T-DNA insertional mutant library of the japonica rice variety Zhonghua 11.All these mutants exhibited as semi-dwarf,reduced leaf angle,whorled primary branches,shortened and widened grains.The same mutant phenotype of F1generated by parallel crossing between three mutants verified that they were allelic.Cosegregation analysis of T-DNA tag confirmed that the mutant phenotypes were not caused by T-DNA insertion in the genome.Three F2 mapping populations were generated by individually crossing mutants with Zhenshan 97.The segregation ratio of mutants and wild-types indicated that the mutant traits were controlled by a single recessive gene (panicle morphological mutant 1,PMM1).Through map-based cloning,PMM1 was located between molecular markers RM3866-1 and X4 (InDel) on the long arm of chromosome 4,with physical region about 147 kb.This research will provide a foundation for further mapping and characterization of the PMM1 gene in rice.