Studies on the Anther Dehiscence in F_1 of Hybrids between Taichung 65 and Its F1 Pollen Sterility Near Isogenic Lines

Japonica rice cultivar, Taichung 65, and its seven F1 pollen sterility near isogenic lines were employed to study the impact of pollen sterility locus on anther dehiscence in hybrid F1 using the anther dehiscence index asindicator. The results showed that the anther dehiscence trait was controlled by genic interaction of pollen sterility loci. Allelic interaction at different pollen sterility loci resulted in different degree of anther indehiscence in hybrid F1. Allelic interaction at S-b locus resulted in part of anther indehiscence in hybrid F1. Genic interaction between pollen sterility loci obviously decreased the anther dehiscent ability. The more heterozygous pollen sterility loci the hybrid F1 had, the worse anther dehiscence the hybrid F1 was. The hybrid of T65×TISL245 had three heterozygous pollen sterility loci, its anther dehiscence index was only 2.27 and the anther dehiscence ability was worst. The main causes resulting in poor anther dehiscence in hybrid F1 were different with the kind and the number of heterozygous pollen sterility loci. The anther dehiscence markedly decreased the total number of pollen grains and the number of pollen grains germinated on stigma. The positive correlation between anther dehiscence index and spikelet fertility was extremely significant.