Limitations of PCR-based molecular markers to identify male-sterile and maintainer plants from Indian onion (Allium cepa L.) populations

摘要

The main aim of this study was to validate PCR markers for determining cytoplasm and genotypes at the Ms locus in short-day onion. Three cytoplasmic (OSN, MKFR and accD) and four nuclear (OPT, jnurf13, AcSKP1 and AcPMS1) markers were employed. Sel. 121-1 had 100% S cytoplasm, whereas Sel. 121-2, Pusa Red' and Pusa Madhavi' had 88%, 33% and 17% S cytoplasm, respectively. Early Grano' and Pusa Riddhi' did not possess S cytoplasm. Observations in 33 commercial varieties revealed two with sterile (S) cytoplasm. Nuclear markers were not found in linkage disequilibrium with the Ms locus, and the constitution of Ms alleles by OPT was different from other three markers, which were in conformity with each other. The other three markers predicted that most of the plants should be homozygous recessive. Anther colour also did not confirm the sterility status. It can be concluded that accD may be used for cytoplasm determination based on the ease of its use. For the Ms locus tagging, more markers are needed to be evaluated to isolate maintainer lines from open-pollinated populations.