Development of a genotyping method for onion (Allium cepa L.) male-fertility based on multiplex PCR

Abstract

ABSTRACTThe most widely used source of onion cytoplasmic male-sterility (CMS) is controlled by a single nuclear gene and a cytoplasmic factor, and the sterility trait can be recovered by the dominant nuclear gene (Ms). Marker-assisted selection (MAS) has a great potential in the selection of male sterility lines and maintainer lines. In this study, two markers at the Ms loci and one cytoplasm marker were used to a develop multiplexed polymerase chain reaction (PCR) system for MAS of fertility traits in onion. Seven pairs of PCR primers were designed on the basis of the flanking sequences (F1890 and S1887) of the male-fertility restoration (Ms) locus and a mitochondrial sequence (mt472) in onion. One set of compatible primers were selected to develop a multiplex-PCR molecular marker (AcCN), which was established in forty-eight lines. The fertility types of cytoplasm and nuclear were distinguished by one-time PCR detection. The accuracy of the AcCN marker was verified in practical backcross breeding population. The AcCN marker types perfectly matched with their genotypes and phenotypes. It can be concluded that this marker is of great practical significance for MAS in the selection of onion maintainer lines.