BT型三系杂交粳稻不同组合间育性差异原因初探

Identifying the Genetic Basis of Spikelet Fertility Differences Between BT-type Three-Line japonica Hybrids

为了阐明不同BT型杂交粳稻组合间育性差异的原因,利用豫粳6号A、9201A及其相应保持系与恢复系TR2604、闵120来配制遗传组合就BT型不育细胞质育性恢复遗传进行研究。根据9201A//9201B/闵120、9201A//9201B/TR2604及豫粳6号A//豫粳6号B/闵120三个群体中植株的育性分离,推断9201A、豫粳6号A的育性恢复均由1对恢复基因控制。基因定位结果表明,恢复系闵120中的恢复基因位于第10染色体上18772374-18967996bp间约195kb物理区间内,TR2604中的恢复基因位于第10染色体18 817 631-18 967 996bp间约150kb物理区间内。根据已克隆Rf1基因的信息可知两恢复系带有的恢复基因均为Rf1a。豫粳6号A/TR2604//TR2604BC1F2群体中植株的Rf1a位点基因型与育性分析结果表明TR2604对豫粳6号A育性恢复由Rf1a控制,豫粳6号A/TR2604不育由双亲间的不亲和性造成。

In order to understand the genetic basis of spikelet fertility differences between BT-type three-line japonica hybrids,the CMS lines Yujing 6A,9201Aand their corresponding maintainer lines,and the restorer lines Min 120,TR2604were used to develop the genetic populations for studying the genetic characteristics of BT-type CMS in different hybrid combinations.According to fertility segregation of the plants from the populations of 9201A//9201B/Min 120,Yujing 6A//Yujing 6B/Min 120and 9201A//9201B/TR2604,it was concluded that the fertility restoration of 9201Aand Yujing 6Awas controlled by one fertility restoration（Rf）gene.Then,the Rfgenes in Min120,TR2604were mapped between 18 772 374-18 967 996bp with the physical distance of 195kb and 18 817 631-18 967 996bp with the physical distance of 150kb on chromosome 10,respectively,indicating that the Rfgenes in Min 120,TR2604might be Rf1aaccording to the mapping results of Rf1in former studies.The fertility restoration of Yujing 6Ain the population derived from Yujing 6Aand TR2604was also controlled by Rf1aidentified by the genotype and phenotype of plants in Yujing 6A/TR2604//TR2604BC1F2population,so the sterility of Yujing 6A/TR2604was induced by hybrid incompatibility between the two parents.