Genetic Variation in Snake Melon (Cucumis melo var. flexuosus) Populations from Jordan using Morphological Traits and RAPDs

Diversity among eight Jordanian snake melon (Cucumis melo var. flexuosus) landrace populations was studied by analyzing morphological traits and random amplified polymorphic DNA (RAPD) markers. Pair-wise euclidean distances based on morphological data ranged from 4.6 to 8.10 among studied populations. Fruit traits explained the variation in the first two components (15.5% and 13.6% of the total variation were explained by PC1 and PC2 respectively), while the leaf traits were consistently present in the third component and therefore contributed less to the variability (10.8%). A total of 11 RAPD primers produced 85 fragments, of which 94% were polymorphic indicating a high degree of diversity. RAPD based dendrogram showed Nei’s values ranging from 0.07 to 0.23 suggesting that the collected populations are genetically diverse. The range of gene diversity, (He) among snake melon populations ranged from 0.17 to 0.27. The analysis of molecular variance (AMOVA) showed that genetic variation among populations accounted for 18.52% of the total variation, while more than 80% occurred within populations consistent with outcrossing nature of snake melon. In conclusion, Jordanian snake melon landraces must be considered as a reservoir of genes that plant breeders need in their snake melon improvement programs.