Li Pingbo, Zhou Hao, Yang Hanyuan, Xia Duo, Liu Rongjia, Sun Ping, Wang Quanxiu, Gao Guanjun, Zhang Qinglu, Wang Gongwei, He Yuqing
National Key Laboratory of Crop Genetic Improvement and National Center of Crop Molecular Breeding, Huazhong Agricultural University, Wuhan, 430070, China.
Rice (N Y). 2020 Feb 10;13(1):11. doi: 10.1186/s12284-020-0372-0.
Wild-abortive cytoplasmic male sterility (CMS-WA) and Honglian CMS (CMS-HL) are the two main CMS types utilized in production of three-line hybrid rice in xian/indica (XI) rice. Dissection of the genetic basis of fertility restoration of CMS-WA and CMS-HL in the core germplasm population would provide valuable gene and material resources for development of three-line hybrid combinations.
In this study, two F populations with CMS-WA and CMS-HL background respectively were developed using 337 XI and aus accessions being paternal parents. Genome-wide association studies on three fertility-related traits of the two populations for two consecutive years revealed that both fertility restoration of CMS-WA and CMS-HL were controlled by a major locus and several minor loci respectively. The major locus for fertility restoration of CMS-WA was co-located with Rf4, and that for fertility restoration of CMS-HL was co-located with Rf5, which are cloned major restorer of fertility (Rf) genes. Furthermore, haplotype analysis of Rf4, Rf5 and Rf6, the three cloned major Rf genes, were conducted using the 337 paternal accessions. Four main haplotypes were identified for Rf4, and displayed different subgroup preferences. Two main haplotypes were identified for Rf5, and the functional type was carried by the majority of paternal accessions. In addition, eight haplotypes were identified for Rf6.
Haplotype analysis of three Rf genes, Rf4, Rf5 and Rf6, could provide valuable sequence variations that can be utilized in marker-aided selection of corresponding genes in rice breeding. Meanwhile, fertility evaluation of 337 accessions under the background of CMS could provide material resources for development of maintainer lines and restorers.
野败型细胞质雄性不育（CMS-WA）和红莲型细胞质雄性不育（CMS-HL）是籼稻三系杂交稻生产中使用的两种主要细胞质雄性不育类型。剖析核心种质群体中CMS-WA和CMS-HL育性恢复的遗传基础，将为三系杂交组合的培育提供有价值的基因和材料资源。
本研究以337份籼稻和澳米品种为父本，分别构建了具有CMS-WA和CMS-HL背景的两个F群体。连续两年对这两个群体的三个育性相关性状进行全基因组关联研究，结果表明，CMS-WA和CMS-HL的育性恢复分别受一个主效位点和几个微效位点控制。CMS-WA育性恢复的主效位点与Rf4共定位，CMS-HL育性恢复的主效位点与Rf5共定位，Rf4和Rf5是已克隆的主效育性恢复基因（Rf）。此外，利用337份父本材料对三个已克隆的主效Rf基因Rf4、Rf5和Rf6进行了单倍型分析。Rf4鉴定出四种主要单倍型，且表现出不同的亚群偏好。Rf5鉴定出两种主要单倍型，大多数父本材料携带功能型单倍型。此外，Rf6鉴定出八种单倍型。
对Rf4、Rf5和Rf6这三个Rf基因进行单倍型分析，可以提供有价值的序列变异，用于水稻育种中相应基因的分子标记辅助选择。同时，对337份材料在CMS背景下的育性评价可为保持系和恢复系的培育提供材料资源。
