The RAPD procedure was used to evaluate genetic diversity of 28 commercial potato cultivars in Iran. DNA of genotypes was extracted from leaves at 3-4 leafy stage by miniprep method. One hundred decamer primers were selected randomly and tested on each sample genotype. Sixteen primers yielded 194 polymorphic DNA fragments (marker), ranging in size from 300 to 2400 bp. A total of 1854 bands were observed among the 28 potato genotypes. Cluster analysis of cultivars was performed based on presence (1) and absence (0) of bands using Jaccards (j.s.c) and Simple Matching Similarity Coefficient (S.M.S.C.) by UPGMA method. These analyses indicated that the greatest genetic difference & similarity was between vlox & herta-2 and herta-1 & herta-2 (plus fersco & ajiba), respectively. Cluster analysis of j.s.c. indicated 7 groupe and that of S.M.S.C indicated 4 groups. Therefore, it was concluded that, j.s.c is more sensitive than S.M.C and is more suitable for comparing cultivar bands produced by RAPD. It was concluded that genetic diversity of potato cultivars was related to their geographical distance and RAPD is useful for classification of germplasm as well as identification of divergent groups.
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