期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：2022
卷号：119
期号：34
DOI：10.1073/pnas.2208759119
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：Significance
Although hybrid rice has been widely utilized for nearly half a century, tremendously improving rice productivity worldwide, the breeding of hybrids has been difficult because of genetic complications in male sterility and fertility-restoring systems currently available in rice. Here, we characterized Fujian Abortive cytoplasmic male sterility (CMS-FA) rice, which has shown stable male sterility controlled by the mitochondrial gene
FA182; a single nuclear gene,
OsRf19, completely restores fertility. This single-gene inheritance has greatly eased the breeding process. By converting CMS-WA hybrids with the CMS-FA system, we developed six hybrids that showed equivalent or better performance relative to their CMS-WA counterparts. CMS-FA/
OsRf19 provides a promising system for future hybrid rice breeding.
Cytoplasmic male sterility (CMS) determined by mitochondrial genes and restorer of fertility (
Rf) controlled by nuclear-encoded genes provide the breeding systems of many hybrid crops for the utilization of heterosis. Although several CMS/
Rf systems have been widely exploited in rice, hybrid breeding using these systems has encountered difficulties due to either fertility instability or complications of two-locus inheritance or both. In this work, we characterized a type of CMS, Fujian Abortive cytoplasmic male sterility (CMS-FA), with stable sporophytic male sterility and a nuclear restorer gene that completely restores hybrid fertility. CMS is caused by the chimeric open reading frame
FA182 that specifically occurs in the mitochondrial genome of CMS-FA rice. The restorer gene
OsRf19 encodes a pentatricopeptide repeat (PPR) protein targeted to mitochondria, where it mediates the cleavage of
FA182 transcripts, thus restoring male fertility. Comparative sequence analysis revealed that
OsRf19 originated through a recent duplication in wild rice relatives, sharing a common ancestor with
OsRf1a/
OsRf5, a fertility restorer gene for Boro II and Hong-Lian CMS. We developed six restorer lines by introgressing
OsRf19 into parental lines of elite CMS-WA hybrids; hybrids produced from these lines showed equivalent or better agronomic performance relative to their counterparts based on the CMS-WA system. These results demonstrate that CMS-FA/
OsRf19 provides a highly promising system for future hybrid rice breeding.
关键词：enricecytoplasmic male sterilityrestorer of fertilityOsRf19hybrid rice breeding
