Diversity in Cucumber Genotypes Based on Morphological Traits and SSR Molecular Markers

Abstract

ABSTRACT: Biodiversity is one of the most important factors in the survival and improvement of any species. Therefore, germplasm collection is the first step for plant improvement. To investigate their genetic and morphological relationships, 10 morphological traits of 20 genotypes of local cucumbers were evaluated using 9 SSR primers. A high genetic variability was observed for the number of flowers per plant. The values of the Jaccard similarity coefficient ranged between 0.51 and 0.92, indicating a high diversity of the genotypes. To evaluate the genetic similarity among genotypes, a cluster analysis using the UPGMA method was performed based on the Jaccard similarity coefficient. The average genetic distance between genotypes (using the Jaccard similarity coefficient) was 0.74 and the mean polymorphic information content (PIC) was 0.69. The primer SSR13251 had the highest PIC (0.8). The clustering pattern of the SSR markers did not coincide with the groupings based on quantitative traits. A dendrogram of the cluster analysis of molecular data showed a high diversity among the studied genotypes. The highest genetic similarity was between genotypes 2 and 3 (0.94), and the lowest genetic similarity was between genotypes 6 and 12 (0.51). The results suggest that SSR markers are a suitable tool to study the genetic diversity and relationships among different genotypes in cucumber.