Genotypic Variability of the Main Apple Cultivars Grown in Transylvania, Romania, Evaluated by Means of RAPD Analysis

Five apple cultivars (‘Florina’, ‘Golden Delicious’, ‘Idared’, ‘Jonathan’ and Starkrimson), were tested in 2004 and 2005 in five commercial orchards located in different counties of Transylvania, Romania, with quite nonsimilar environments. In June, young shoots were harvested from each cultivar and taken to the laboratory by means of a refrigerating bag. Young leaves were harvested from the shoots and preserved in refrigerator at –70oC until the DNA extraction was performed. Twelve decamer primers were used for DNA amplification out of which ten produced polymorphic bands in each cultivar/location. A dendrograms was constructed based on DNA migration in agarose gel and analysis of formed bands and genetic distances, for revealing the intervarietal polymorphism in the five locations. As it has been expected, at the molecular level there were great differences among the tested cultivars, but the dendrogram also exhibited the existence of obvious differences, at the molecular level, within the same cultivar, depending on location. Such differences should be attributed mainly to the lack of uniformity of initial mother plants used in the process of planting material production for the five cultivars under study. It is concluded that RAPD analysis could successfully be used in checking the authenticity of planting material for apple trees produced in different nurseries, provided there are available standard forms of the interested cultivars from which DNA could be analyzed and used as control