Abstract:

This study aims to develop a stable and reliable molecular marker of onion fertility locus and apply it to breeding practice for screening breeding lines, which will further shorten the breeding cycle, save breeding costs, and accelerate the cultivation process of onion hybrids. Based on the AFLP sequences of onion fertility restoration Ms locus, WH-SSR-1 molecular marker was developed, identified and applied in breeding practice by sequence alignment analysis, PCR detection and phenotype analysis. The results showed that WH-SSR-1 marker was closely linked to Ms locus. When Ms locus genotype was homozygous dominant MsMs, there was one 102 bp band; when Ms locus genotype was homozygous recessive msms, there was only one 99 bp band; when Ms locus genotype was hybridized Msms, there were two bands, 102 bp band and 99 bp band, respectively. The validation results of 32 onion materials confirmed that the marker type of Ms locus was completely consistent with the genotype. Subsequently, two matching maintainer and sterile lines were directly developed from four OP populations, but ‘Diaoyu’ and ‘Tianzhenghongyu’ could not be easily matched because no maintainer or sterile individuals were detected. The WH-SSR-1 marker is closely linked to Ms locus and can be used in the breeding practice. The maintainer and sterile individuals can be directly selected from OP population, and can be matched with each other and form counterpart breeding lines at the same time.

Key words: onion (Allium cepa L.), maintainer line, male sterile line, Ms locus, SSR marker