Yang Liu, Zuopeng Xu, Yuanyue Du, Benxi Huang, Meng Li, Lijia Zhang, Xiangqiang Zhao, Qiaoquan Liu, Shuzhu Tang & Honggen Zhang

Theoretical and Applied Genetics; December 2023; vol. 136; Article 248

Three-line hybrid rice has primarily been developed on wild abortive (WA)-type cytoplasmic male sterility (CMS) and has helped increase the yield of rice globally. The development of WA-type CMS lines and hybrids was expedited through the identification and mapping of the fertility restorer gene (Rf) in maintainers. This study observed fertile plants in WA-TianfengA/Zhenshan97B//TianfengB population, indicating that the maintainer line ‘Zhenshan97B’ should carry Rfs for WA-type CMS. Several advanced backcross populations were generated with the genetic background of the ‘WA-TianfengA,’ and the pollen fertility levels of the backcrossed individuals in BC₃F₁, BC₄F₁ and BC₄F₂ populations are governed by a new gene, Rf20(t), from ‘Zhenshan97B.’ Employing bulk segregant analysis of fertile and sterile pools from the BC₄F₁ population, Rf20(t) was genetically mapped to a candidate region on chromosome 10. Subsequently, Rf20(t) was located between RM24883 and RM24919 through recombination analysis of molecular markers using the BC₄F₂ population. Implementing a substitution mapping strategy, Rf20(t) was ultimately mapped to a 245-kb region between the molecular markers STS10-122 and STS10-126 and obtained the most likely candidate gene LOC_Os10g02650, which is predicted to encode pentatricopeptide repeat-containing (PPR) protein. These results enhance our understanding of the fertility restoration of WA-type CMS lines, facilitating the development of high-quality pairs of WA-type CMS and maintainer lines.

See https://link.springer.com/article/10.1007/s00122-023-04486-9