Marker assisted selection of male sterile (CMS-S) lines among short day Indian onion genotypes

The study attempted to find male-sterile lines among forty-eight—open pollinated onion genotypes (Allium cepa L.) by genotyping followed by phenotyping, and were essential for the development of CGMS (cytoplasmic-genic male sterility) based onion hybrids. In order to identify the CMS-S cytoplasm and the normal (N) cytoplasm locus, two sets of simple PCR markers linked to orf725 gene was utilized. The study resulted in the identification of male sterile CMS-S cytoplasmic lines DOGR-MG-2 and DOGR-MG-70 by marker-assisted selection using orf725 gene specific markers. This was validated through phenotyping using the block card assay and acetocarmine test. The markers are specific to orf725 gene and linked with CMS-S cytoplasm markers, hence markers were effectively employed and isolated CMS-S cytoplasmic lines. The marker-assisted selection of CMS-S locus greatly benefits from the employment of these molecular markers. In this regard, the study showed that use of verified markers across genotypes is crucial to advance generation of F₁ onions using marker-assisted breeding programme.