Investigation of genetic diversity of squash (Cucurbita maxima Duchesne) genotypes collected from Erzincan in Turkey

Plant genetic resources constitute the most valuable assets of countries. It is of great importance to determine the genetic variation among these resources and to use the data in breeding studies. Cucurbita maxima species in the Cucurbitaceae family have high genetic diversity, but molecular genetic diversity studies of this species are insufficient in Turkey. To determine the genetic diversity among genotypes of Cucurbita maxima species of squash, which is widely grown in Erzincan, 14 different squash genotypes collected were examined based on the morphological parameters and molecular characteristics. According to the evaluated morphological characteristics, we can say that genotype 5 should be evaluated in breeding programs. In addition, in crossbreeding studies, the heterosis feature is more successful in types with a long genetic distance. In the study, the longest genetic distance was found between genotypes 5 and 48. Simple sequence repeat (SSR) markers were used to determine genetic diversity at the molecular level. The analysis of morphological characterization within genotypes showed a wide variability in morphological traits of plant, flower, fruit, and leaf. Seven SSR markers yielded a total of 23 polymorphic bands, the number of alleles per marker ranged from 2 to 5, and the mean number of alleles was 3.286. Polymorphic information content (PIC) ranged from 0.00 (GMT-M61) to 0.202 (GMT-P25), and the mean PIC value per marker was 0.130. Cluster analysis using Nei's genetic distance determined that 14 genotypes were divided into 3 major groups. © 2022, College of Life Science. All rights reserved.