Abstract
BackgroundWild-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.ResultsIn this study, two F1 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.ConclusionsHaplotype 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.
Highlights
Wild-abortive cytoplasmic male sterility (CMS-WA) and Honglian Cytoplasmic male sterility (CMS) (CMS-HL) are the two main CMS types utilized in production of three-line hybrid rice in xian/indica (XI) rice
The pollen fertility of the F1 population with Honglian CMS (CMS-HL) was excluded in this study
CMS-HL In this study, Genome wide association studies (GWAS) revealed that fertility restoration of Wild-abortive CMS (CMS-WA) was mainly conditioned by the major gene Rf4, as the remaining loci could not be repeatedly detected in 2 years and accounted for less variation (Table 1)
Summary
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. Cytoplasmic male sterility (CMS) in higher plants is characterized by the inability to produce functional pollens, and is caused by chimeric open reading frame (ORF) in the mitochondrial genome. Nuclear-encoded restorer of fertility (Rf) genes produce proteins that are targeted to mitochondrial and can suppress the function of ORFs conferring CMS (Chen and Liu 2014). Wild-abortive CMS (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, and CMS-WA is a typical sporophytic type while CMS-HL is a gametophytic type (Li et al 2007).
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
