Comparative analysis of fertility restoration genes for WA, Y, and DA cytoplasmic male sterility in rice

Abstract

Rice chromosome single segment substitution line (SSSL) W23-19-06-06-11 with the genotype Rf3Rf3/Rf4Rf4, a strong restorer line for wild-abortive (WA) cytoplasmic male sterility (CMS), was recently identified from the SSSL library. To investigate the genetic mode of Rf genes and the genetic relationship among WA, yegong (Y), and dwarf-wildabortive (DA) CMS systems, the plants derived from three BC3F2 populations involving W23-19-06-06-11 and the three CMS lines, that carried the Rf3Rf3/Rf4Rf4, Rf3Rf3/rf4rf4, and rf3rf3/Rf4Rf4 genotypes and WA-, Y-, and DA-CMS cytoplasm, were selected and their pollen and spikelet fertility were evaluated. The results show that the genetic effect displayed a trend of Y-CMS > WA-CMS > DA-CMS in the genetic background of W23-19-06-06-11, the effect of Rf4 appeared to be slightly larger than that of Rf3, and their effects were additive for the three CMS systems. Two pairs of dominant genes governed the fertility restoration in pollen and spikelet in the W23-19-06-06-11 which indicates that the genetic mode of the Rf genes was a qualitative character for the three CMS systems.