Abstract:In the research of constructing a rice(Oryza sativa) molecular map, 4 RFLP markers, i.e. RG 229, RG 419, RG 424 and RG 353, detected the null alleles in the indica and japonica parental rice. RG 229 indicated two null alleles in indica rice Gui 630, and each of the other markers revealed a null allele in japonica rice 02428. Genetic analysis in the doubled haploid (DH) population consisting of 81 plants showed that the linkage relationships between these null allele loci and the neighboring molecular markers shown in McCouch‘ s rice molecular map were changed. In addition, the marker RG 684 could detect its null alleles in some DH plants, though the RG 684 sequence did exist in the genomes of both parents. Appearence of null alleles might be induced by transpositional changes on chromosomes.