Perspective and application of molecular markers linked to the cytoplasm types and male-fertility restorer locus in onion (Allium cepa)

Abstract

The male sterility trait is an economically essential feature for the exploitation of hybrid vigour in onions; hence, scientists have looked into the molecular component of male sterility in onions. As a result, numerous molecular markers associated with male-sterile (CMS-S and CMS-T) cytoplasms, male-fertile normal (N) cytoplasm and nuclear-male-fertility restorers (Ms locus) were developed. The discovered markers have proven to be helpful in the effective selection and isolation of male-sterile lines, their maintainer lines and restorer-of-fertility lines. These lines are required for breeding F1 hybrid to harness heterosis through marker-assisted selection (MAS) of cytoplasmic genotypes with Ms or ms loci. Thus, the study came up with a compilation of molecular markers, by revealing their molecular perspective, practical utility and functional effectiveness in the MAS of male-sterile cytoplasm types with nuclear-fertility-restorer locus, to speed up onion breeding, development of F1 hybrids and production of pure hybrid seeds.