Work

Development and application of KASP markers for cytoplasmic male sterility genes in polima CMS and ogura CMS systems in rapeseed (Brassica napus L.)

Year: 2026

Type: article

Abstract: The cytoplasmic male sterility (CMS) is the main strategy for exploiting heterosis in rapeseed, with Polima CMS (Pol CMS) and Ogura CMS (Ogu CMS) being the most widely utilized systems. To enable high-throughput identification of cytoplasm types, we developed four Kompetitive Allele-Specific PCR (KASP) markers targeting or flanking the mitochondrial sterility genes orf224/atp6 (Pol CMS) and orf138 (Ogu CMS). Genotyping of 101 rapeseed accessions with diverse genetic backgrounds demonstrated accurate discrimination of cytoplasm types by these markers. By combining the above cytoplasmic markers with markers for the nuclear fertility restorer gene ( Rf ), we established a dual-marker system capable of simultaneously determining cytoplasmic type (S/N) and nuclear genotype ( RfRf / Rfrf / rfrf ). This system enables systematic tracing of the specific causes of purity decline in male-sterile lines, restorer lines, and hybrids, with results fully consistent with field phenotyping. Furthermore, using this dual-marker-assisted selection strategy, we efficiently identified 24 isoplasmic restorer lines from 187 germplasm accessions. In conclusion, the KASP markers developed in this study provide an efficient and precise tool for identifying mitochondrial sterility genes in the Pol CMS and Ogu CMS systems, thereby substantially improving the efficiency of parental line identification and purity assessment.

Source: Molecular Breeding

DOI: 10.1007/s11032-026-01737-7