ISOZYME VARIATION IN CUCUMBER (CUCUMIS-SATIVUS L)

The Indian wild cucumber (Cucumis sativus L. var. hardwickii Kitamura) and 81 accessions of cucumber (C. sativus) were examined for isozyme variations of six enzymes. Variations were observed in malate dehydrogenase (MDH), 6-phosphogluconic dehydrogenase (6-PGD), phosphoglucomutase (PGM) and phosphoglucose isomerase (PGI), whereas shikimate dehydrogenase (SKDH) and isocitrate dehydrogenase (IDH) were found to be monomorphic. The variations implied that the Indian wild cucumber is a distant relative of the cultivated cucumber, but the relationships between ecotype differentiations among cucumber cultivars and isozyme phenotypes were not recognized. The one-seed analysis of MDH isozymes was useful in evaluating the seed purity of F1 cucumber, since the isozyme variations were scattered in commercial cultivars in respective diverse ecotypes.