Abstract:To study the inheritance pattern of a new male sterile mutant in maize. The sibling population of maize K305 male sterile mutant induced by 60Co-γ irradiation was planted in different locations, years and seasons, the male sterility was identified by using interior microscopic examination of pollen and the field investigation method. The nucleus effects were analyzed by the sister crosses, test crosses, and their selfing and backcross progenies with the sterile plants as females. The cytoplasm effects were investigated through analyzing the reciprocal F1 and F2 with normal inbred lines as females, and the fertility fully recovered test crosses and fertile sibling as males, respectively. The results showed that the male sterile plant exhibited closed glumes, empty anther, complete and stable sterility. The segregation ratio of fertile to sterile plants was 1:1 in the sibling and backcross populations, while 3:1 in the fertile selfing population, and the heredity of the male sterility was not associated with the varied cytoplasm. The demonstrated that the mutant, belonged a pollen-less type, was a genic male sterility controlled by a single recessive gene, which laid the foundation for further utilization.