Evolutionary relationship and divergence among six cultivars of trichosanthes anguina l. based on sds-page and rapd analysis

A set of 6 cultivars of snake gourd (Trichosanthes anguina) collection was subjected to sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) and Random amplified polymorphic DNA analysis (RAPD) analysis. By using SDS-PAGE, total soluble leaf protein was fractionated into 11 bands, which showed heterogeneity among different varieties. Thiruvallur cultivar (TVL) exhibited maximum number of bands (11) and Nagapattinum cultivar (NAP) exhibited least number of 6 bands. Polymerase chain reaction (PCR) with 4 arbitrary decamer oligonucleotide primers, applied to the 6 cultivars, produced a total of 46 different marker bands of which 63.4 per cent were polymorphic. The size range of the amplified DNAs was mostly between 106 bp and 6132 bp. Thus, with the selected primers sufficient polymorphism could be detected to allow identification of individual cultivars. Visual examination of electrophoresis gels and analysis of banding patterns confirmed that many of the snake gourds under cultivation with similar morphological characters are genetically quite different. A dendrogram displaying the relative genetic similarities between the cultivars showed a range of 56 to 89 per cent similarity. RAPD analysis offered a rapid and reliable method for the estimation of variability between different cultivars which could be utilized by the breeders for further improvement of the snake gourd genotypes.