Submitted to: Plant Genetic Resources
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/28/2008
Publication Date: 3/5/2009
Citation: Nimmakayala, P., Tomason, Y.R., Jeong, J., Vajja, G., Levi, A., Gibson, P., Reddy, U.K. 2009. Molecular Diversity in Ukrainian Melon Collection as Revealed by AFLP and Microsatellite Markers. Plant Genetic Resources, online publication http://journals.cambridge.org/action/displayIssue?jid=PGR. doi:10.1017/S1479262108098481
Interpretive Summary: There are approximately 95,000 acres of cantaloupes in the US and there is a continuous need to improve melon cultivars for disease and pest resistance. Also, there is great interest by consumer groups and by the melon industry to improve the nutritional quality of melons. Accessions of melons collected in different parts of the world are important sources of genes that confer disease and pest resistance and of genes that can improve melon fruit quality. Melon has been cultivated in the Ukraine and in neighboring countries (including Uzbekistan, Tajikistan, and Kazakhstan) for over 1,500 years. There are several attributes of Ukraine melons (e.g., pest and disease resistance, fruit quality, and long shelf life) that might be useful for improving U.S. melon. However, there is no information about the genetic diversity that exists among Ukrainian melon accessions. Knowing the extent of genetic diversity among these accessions can allow plant breeders to use them more effectively in their breeding programs aimed of improving melon cultivars in the US. In this study, we examined genetic differences among the Ukrainian melon accessions using DNA markers. The data from this study indicates that extensive genetic diversity exists among the Ukrainian melons. This information will prove useful to plant breeders in interbreeding the Ukranian melons with US melons to introduce new and useful traits into future US melon varieties.
Technical Abstract: Thirty-eight melon accessions, which are of primary breeding importance in the Ukraine, were analyzed for diversity. These collections represent a major non-US and non-west Europe source of melon germplasm that have not yet been subjected to molecular characterization. Molecular diversity was estimated based on a robust set of 465 polymorphisms gathered by Amplified Fragment Length Polymorphisms (AFLP) and Simple Sequence Repeats (SSR). In this paper, we report 12 newly developed polymorphic SSR primer pairs, and their use for molecular characterization in the Ukrainian melon collections. Based on these polymorphisms, we estimated similarity indices that ranged from 0.70 to 1.00 among various accessions. The phylogenetic tree based on the similarity indices and a three dimensional plot of the first three vectors of the principal component analysis corresponded fairly with the existing three classical morphotypes namely aestivalis, europeus and hiemalis, under the convar Europeus, which also is known as adana. The polymorphisms generated in the current study are specific to the grouping of fruit types and days to maturity would be very useful for further genetic studies and marker assisted selections.