萍乡核不育水稻的新恢复系及遗传分析

摘要

In construction of Pingxiang Dominant Genic Male Sterile Rice (PDGMSR) sterile gene mapping population, we found some reported maintainer lines shown the fertility restoration ability.Thus, this study systemly analyzed the fertility separation of F1,F2 and F3 populations of the crosses between the PDGMSR and the reported maintainer lines.We observed that the progenies from sib-crosses between male-sterile plant and fertile plant of the PDGMSR were always segregated in a ratio of 1 male-sterile to 1 fertile.The male-sterile plant could be fertile when kept in high temperature during the stage of young panicle development, and the selfed progenies gave a ratio of 3 male-sterile to 1 fertile.The progenies of F1 from PDGMSR crossed with Gui 99, Teqing and 9311BB23 were complete fertile, indicating that Gui 99, Teqing and 9311BB23 have restoration ability.Half of the F2 populations derived from the F1 plants of PDGMSR crossed with Gui 99 or Teqing or 9311BB23 were complete fertile and the other half of the F2 populations showed fertility segregating with the ratio of sterile plants to fertile plants of 3∶13.Among the F3 families derived from the fertile plants in the segregating F2 populations, the ratio of the complete fertile F3 families to the fertility-segregating F3 families was 7∶6.These results indicate that Gui 99, Teqing and 9311BB23 have restoring gene which shows dominant epistatic fertility restorer ability for PDGMSR and inhibits the expression of the dominant sterile gene in PDGMSR and consequently transfer the sterility to fertility.%在构建萍乡核不育水稻显性核不育基因定位群体时,我们意外发现一些前人报道的保持系表现出恢复性,为此本试验对这几个品系与萍乡核不育水稻杂交后代育性分离做了系统的分析.结果表明,萍乡核不育水稻不育单株与可育单株杂交F1代的不育株与可育株按1:1分离,高温自交后代不育株与可育株按3:1分离.萍乡核不育水稻不育单株分别与桂99、特青和9311BB23杂交,它们的F1代均可育,表现恢复性.由F1代产生的F1:2家系中出现全可育群体和育性分离群体的比例为1:1.其中育性分离群体中不育株与可育株按3:13进行分离.从育性分离的F1:2家系中的可育株自交产生的F2:3家系出现全可育群体和育性分离群体的比例为7:6.这些分离规律表明,桂99、特青和931IBB23具有恢复基因,并对萍乡核不育水稻的显性核不育基因表现出显性上位作用,能抑制显性不育基因的表达,从而使不育性转变为可育.