水稻新不育系科丰A显性早熟性的遗传机制分析

Genetic Mechanism of the Dominant Earliness in Kefeng A,a New Cytoplasmic Male Sterile Line in Rice

籼型细胞质雄性不育系科丰A表现出早熟性,该不育系与晚籼恢复系所配组的F1都呈现不同程度的显性早熟现象。为了解该不育系显性早熟性的遗传机制,利用一整套抽穗期感光基因近等基因系EG0～EG7、ER、LR、T65、T65Eb、T65Ebm、T65m、NIL(Hd1)和NIL(Hd4)等对科丰A抽穗期感光基因的基因型进行了初步分析。结果表明,科丰A的抽穗期基因型为E1E1e2e2E3E3Se-1uSe-1uEf-1Ef-1,并带有感光基因E1的显性抑制基因(暂定名为Su-E1)和感光基因Se-1u的隐性抑制基因(i-Se-1)。分析了由该不育系配组的杂种F1表现早熟现象的原因,并探讨了科丰A所带早熟相关基因的育种利用价值。

Kefeng A is an early maturing cytoplasmic male sterile line of indica rice. Hybrids derived from Kefeng A and late maturity indica restorer lines showed dominant earliness. To understand the genetic basis of dominant earliness, genotype of photoperiod sensitivity genes in Kefeng A was analyzed using a set of heading time near isogenic lines EGO to EG7, ER, LR, T65, T65Eb, T65Ebm, T65m, NIL（Hd1 ） and NIL（Hd4）. Results indicated that the genotype of photoperiod sensitivity genes for heading time in Kefeng A was E1 E1 e 2 e2 E3 E3 Se-1 ^uSe-1 ^uE f-1 E f-1. Based on the detected heading time genotype, in combination with the heading time of Kefeng A and the early maturing phenomenon in its F1 hybrids, it was speculated that Kefeng A carries a dominant inhibitor gene for the dominant photoperiod sensitive gene E1 , putatively designated Sw-E1 , and a recessive inhibitor gene for another dominant photoperiod sensitive gene Se-1 , namely i-Se-1. The reason why F1 hybrids derived from Kefeng A exhibited earliness was analyzed and the breeding value of dominant earliness related genes in Kefeng A was discussed.