Multiple pistillate male sterile rices for hybrid seed production

摘要

The multiple pistil japonica rice WX154 appeared to be single recessive in the cross between WX154 and a japonica, Suweon 295, but duplicate recessive in the cross between WX154 and an indica, HR1619-6-2-1-2-2. The multiple pistil of the indica cultivar Double Rice was controlled by a single recessive gene in the crosses between Double Rice and indica rice cultivars IR36ms and HR1619-6-2-1-2-2. The florets and grain structure of F 1 s of the crosses between the multiple pistillate rice cultivar and the normal pistillate cultivars were normal. The multiple pistillate lines derived from R1619-6-2-1-2-2/Double Rice were crossed to the cytoplasmic male sterile (CMS) rice HR1619 A having wild abortive cytoplasm. The sterile F 1 plants were backcrossed to the maintainer multiple pistillate lines. The multiple pistillate cytoplasmic male sterile (MPCMS) lines with semidwarfness could be selected from those backcross progenies. The panicles per hill and florets per panicle of the MPCMS lines did not differ from those of the CMS lines with normal pistils. The multiple pistillate genetic male sterile (MPGMS) lines could be selected from the F 4 of the cross lR36ms/Double Rice. Fewer panicles per hill and florets per panicle were observed in the MPGMS lines than in the genetic male sterile (GMS) lines with normal pistils. The average outcrossing of the multiple pistillate male sterile lines in CMS or in GMS rices was statistically not higher than that of the male sterile lines with normal pistils. Larger variation of outcrossing rate was observed in the multiple pistillate male sterile rices than in the normal pistillate male sterile ones. The outcrossed seed setting percentage of the MPCMS lines ranged from 1.1 to 34.8% and that of the MPGMS lines ranged from 0.1 to 40.5%. The outcrossing percentage of the CMS lines ranged from 1.2 to 21.3% while that of the GMS lines ranged from 1.5 to 36.7%. Seed setting percentage of the artificial cross in the MPCMS lines was significantly higher than in the CMS lines.