Morphological and molecular characterization of onion (Allium cepa L.) genotypes using RAPD markers

Abstract

The present study carried out to with a view to characterize and validate the RAPD marker's genetic diversity at morphological and molecular levels in thirty cultivars of onion (Allium cepa L.). This work aimed to determine their important traits, DNA polymorphism and decipher their genetic variation. The agro-morphological characters such as germination percentage, plant height, leaf colour, leaf waxiness, leaf foliage attitude, bulk colure and bulk shape of thirty onion genotypes were studied. The genetic diversity assessed using four RAPD markers (OPB-09, OPA-16, OPB-16, and OPA-09). It revealed significant genotypic differences in the onion genotypes. Significant genetic diversity was observed and revealed by UPGMA analysis. The RAPD analysis yielded 98.21% average polymorphism (genetic diversity) with 901 amplicons. The OPA-16, OPB-16, and OPA-9 showed 100% polymorphism and only OPB-9 produced 92.85% polymorphism. The RAPD primers discriminated thirty cultivars into two major clusters by the method of UPGMA. The major cluster (cluster-A) contains 28 genotypes and another was a minor cluster (cluster-B) which contains only two genotypes (1403 and 1432/33). The cultivars exhibited statistically significant variability, which gives an opportunity to use them for varietal development through breeding programs. The key findings of the current study would be an insight for breeding strategies in onion cultivars.