Fine mapping of <italic>Rf2</italic>, a major locus controlling pollen fertility restoration in sorghum A1 cytoplasm, encodes a PPR gene and its validation through expression analysis.

Abstract: Sorghum is one of the pioneering cereal crops where cytoplasmic male sterility (CMS) was successfully exploited for mass production of F1 hybrid seed. Mapping genes for fertility restoration (<italic>Rf</italic>) is an important aspect of understanding the molecular basis of fertility restoration in crop plants. In this study, we fine‐mapped a fertility restoration locus, <italic>Rf2</italic> of sorghum reported earlier (Jordan, Mace, Henzell, Klein, & Klein, ), involving two F2 populations (296A × RS29 and 296A × DSV1) and newly developed SSR markers delimited <italic>Rf2</italic> locus to 10.32‐kb region on chromosome 2. The <italic>Rf2</italic> locus was tightly linked with two new SSRs, MS‐SB02‐3460 (0.14 cM) and MS‐SB02‐3466 (0.75 cM) on both sides, and hosted only one gene (<italic>Sobic.002G057050</italic>) of PPR gene family. Another new SSR marker developed in the study, MS‐SB02‐37912, forms the part of PPR gene and could act as a perfect marker in marker‐assisted breeding for fertility restoration involving <italic>Rf2</italic> in sorghum breeding. The strong involvement of <italic>Sobic.002G057050</italic> gene in fertility restoration was supported through RNA expression analysis. [ABSTRACT FROM AUTHOR]