Determination of genetic diversity in cucumber (Cucumis sativus L.) germplasms

Abstract

In this study, 92 Turkish cucumber (Cucumis sativus L. var. sativus) accessions were characterized by using SRAP (Sequence Related Amplified Polymorphism) which is a PCR-based moleculer marker system. A total of 45 SRAP combinations were used and 31 of these combinations amplified well and also showed polymorphism. Thus, 153 SRAP fragments were obtained and 138 fragments were polymorphic. These data were used to determine genetic distance and draw genetic distance dendrograms of Turkish cucumber accessions. Dendrograms were drawn using both UPGMA (Unweighted Pair Group Method) arithmetical averages and Unweighted Neighbour-Joining methods. According to the UPGMA dendrogram, the cucumber accessions clustered into four groups. Group B was composed of the genetically most related accessions with a minimum similarity of 0,82. Group D was composed of genetically most distinct accessions. The genetic distances of the dendrogram varied between 0,16 and 0,99. The neighbourjoining dendrogram showed similar clustering of the cucumber accessions. The results showed that Turkish cucumber is genetically quite diverse and has the potential for broadening the genetic base of cucumber.