Morphological and Molecular Diversity Analysis among Selective Varieties of Pumpkin (Cucurbita Maxima) and Bottle Gourd (Lagenaria Siceraria) Using RAPD Markers

Abstract

An experiment was carried out to study the morphological and yielding performance of four pumpkin and four bottle gourd genotypes at phenotypic level, to determine the relationship and diversity among the individual genotypes at molecular level through RAPD markers during the period from July 2012 to April 2014. Variation was found among the genotypes for first flowering date, first fruiting date, leaf color, leaf size, fruits per plant, fruit weight, 100-seed weight etc. For molecular characterization, in a total of 9 DNA bands were scored by using three selected random primers (A17, A21 and A24) of which 7 (77.78%) bands were proved to be polymorphic. The highest gene frequency of polymorphic loci was 0.8750 for A24-3 and A24-5. The highest gene diversity value was 0.5000 for A21-1 and A24-1. The highest genetic diversity among genotypes found in pumpkin Sweety and the lowest found in Bari lau. The average co-efficient of gene differentiation (Gst), gene flow (Nm) and Shannon's Information Index values were 1.0000, 0.0000 and 0.4252, respectively. Based on pair-wise comparison of RAPD amplification products, genetic similarity was estimated using Nei's (1972) genetic distance and a dendrogram was constructed using unweighted pair group method of arithmetic mean (UPGMA). The results of cluster analysis indicated that eight genotypes were classified into two major groups: pumpkin Sweety (Hybrid), Metal (Hybrid), Alamin (Local), Dewan (Local) and bottle gourd Lalima (Local), Higreen (Hybrid) were included in cluster I while were Bari lau (Local) and Martina (Hybrid) genotypes in cluster II. The pumpkin Alamin (Local) was closer to the bottle gourd variety Martina (Hybrid) (0.0000) and the highest genetic distance was found between pumpkin Alamin (local) and bottle gourd Bari lau (Local) and pumpkin Dewan (local) and bottle gourd Bari lau (Local). Each cluster further divided into two sub clusters. This result indicates that the varieties which formed grouped together, they are less diversed. On the other hand the varieties remain in different clusters or different groups are much diversed. Thus RAPD perform a potentially simple, rapid and reliable method to evaluate genetic diversity and molecular characterization as well.