Identification of SSR markers linked to new fertility restoration trait in sorghum (Sorghum bicolor (L.) Moench) for A4 (maldandi) male sterile cytoplasm

Abstract

AbstractIdentification of markers associated with fertility restoration (Rf) genes is essential because they can streamline the breeding of new CMS lines and production of commercial hybrid seeds. Therefore, in the present study, F2 populations (M31‐2A × DSMR 8) was utilized to identify markers linked to Rf loci on maldandi (A4) cytoplasm through bulk segregant analysis (BSA). The F2 population was analysed for seed set percentage. Chi‐square (χ2) analysis showed that the fertility restoration trait followed expected digenic ratio. By BSA, simple sequence repeats (SSRs) markers, namely, Xtxp 34 and Xtxp 69 located on chromosome 3 and SB 3956 and Xtxp 312 located on chromosome 7, showed clear polymorphism between two groups of fertile and sterile bulks. The genomic region harbouring Rf locus on chromosome 3 (2.61 Mbp) predicted to encode five pentatricopeptide repeat (PPR) genes whereas, on chromosome 7, the gene SORBI_3007G047400 predicted to encode MYB (myeloblastosis) domain containing proteins. These predicted genes could be the candidate for restoring fertility on A4 cytoplasm. This finding will be fundamental in the production and rapid selection of novel restorer lines.