Genetic Diversity in Muscadine and Bunch Grapes Based on RAPD Analysis
Two morphologically very distinct grapevines belonging to the subgenera Euvitis and Muscadinia of the genus Vitis are cultivated in the United States. The former is commonly called “bunch” grape, while the latter is usually called “muscadine.” Genetic diversity among these grapes was investigated based on random amplified polymorphic DNAs (RAPDs). Sixteen grape cultivars, with their parentage including V. rotundifolia, V. vinifera, and several American Vitis species, were used for the RAPD analysis. More than 200 RAPDs were produced from 20 random primers. More than 90% of which were polymorphic between the muscadine and the bunch grapes, while polymorphism was considerably low within the muscadine and the bunch grapes. The relationships of grapes between these two subgenera were estimated based on bandsharing and cluster analysis. The result based on the DNA analysis agrees with the isozyme data obtained from a separate study, which demonstrated that the muscadine grape shares very low common alleles with the American bunch grapes and the European grapes.