Mapping QTLs for Fertility Restoration of Different Cytoplasmic Male Sterility Types in Rice Using Two Backcross Inbred Line Populations.

Hybrid rice breeding using cytoplasmic male sterility/fertility restoration (CMS/) systems plays an important role in ensuring global food security. Two backcross inbred line (BIL) populations derived from either Xieqingzao B (XB)//XB/Dongxiang wild rice (DWR) (XXD) or XB//DWR/XB (XDX) were used to detect quantitative trait loci (QTLs) for fertility restoration of Dwarf wild abortive- (DA-), Indonesia Paddy- (ID-), and DWR-type CMS in rice. Lines with ID- and DA-type CMS were testcrossed with both the XXD- and XDX-BILs, while the line with DWR-type CMS was testcrossed with the XDX-BILs only. A total of 16 QTLs for fertility restoration of CMS systems were identified, including three for DWR-type CMS, six for DA-type CMS, and seven for ID-type CMS. All of the additive alleles in the QTLs were derived from . Eleven QTLs were clustered in five chromosomal regions, indicating that common loci restored different CMS systems, and the favorable . alleles could be used to develop restorer lines for various CMS types by marker-assisted selection.