Study on variation of potato varieties using electrophoretic tuber storage proteins

Storage protein banding patterns of 13 varieties of potato (Solanum tuberosum L.) were compared by sodium dodecylsulfate polyacrylamide gel electrophoresis (SDS-PAGE). Certain bands could be easily used by researchers to identify varieties under study or their hybrids. Tuber of potatoes that formed in farm were used as the source of plant materials. SDS-PAGE gave 30 protein bands in the 6.5-205 kDa molecular weight range, including 4 major bands (A, B, C, D), 11 prominent bands and 15 minor bands. Three major bands B, C and D at 23 to 25 kDa positions could be probably the isomers of the storage proteins, sporamin. Another thick band (A) at 40 kDa position was identified as patatin. Both sporamin and patatin appeared to be useful indicators of the percentage of protein present in a cultivar. Protein profiles were used to estimate the genetic distance among the varieties. They were clustered together between around 0.16 to 0.52 level of distance, with a mean value of 0.34, showing that the genetic dissimilarity between potato varieties is smaller than their similarity (1-0.34 = 0.66). Cluster analysis differentiated 13 varieties in 4 groups: (1) Fina (2) Bolesta, Marifona, Diamant and Bright (3) Agria, Cosmos, Herta, Romano Kondor and Ditta (4) Santi and Picasso. Romano and Kondor varieties were the most similar but the most dissimilar one was Finna.