Genetic Variation among <i>Cucurbita pepo</i> Accessions Varying in Seed Nutrition and Seed Size

Abstract

Pumpkin seed (Cucurbita pepo L.) is a nutritionally valuable food and a significant source of income globally. Pumpkin seeds are rich in oil, protein, unsaturated fatty acids and tocopherols, which are associated with improved human health. Understanding the genetic diversity among pumpkin accessions varying in seed nutrition traits is necessary for designing sound breeding strategies for developing superior cultivars. In the current study, 26 simple sequence repeats (SSR) markers were used to assess genetic relatedness among 29 C. pepo accessions varying in seed oil, seed protein, seed-coat phenotype, seed size and fatty acid composition. The SSR markers revealed 102 alleles averaging 3.92 alleles per loci and mean polymorphic information content (PIC) of 0.44. Eleven of the markers had a PIC of ≥0.5. Ward dendrogram and principle component analysis based on seed traits grouped the genotypes into two major clusters corresponding to subspecies pepo and texana, with all the reduced-hull accessions grouping within the former. Collectively, this data suggests wide phenotypic (seed traits) and genotypic variation within C. pepo that may be exploited to develop superior reduced-hull cultivars.

Determination of Genetic Diversity in Some Pumpkin Genotypes Using SSR Marker Technique

“…This may be due to the use of different pumpkin subspecies as genetic resources. In this study, genetic diversity among C. pepo populations was found to be narrower than in some studies [24,38]. This may be because these populations congregate from a narrow location.…”

“…Kayak et al, [37] determined the number of bands per primer to be 3.9 using SSR markers in the pumpkin genotypes in their study. Meru et al, [38] obtained an average of 3.92 alleles per locus in their study with SSR primer on 29 pumpkin genotypes. In a study on C. pepo genotypes, an average of 4.12 bands was obtained from SSR primers [39].…”

“…The wider variation may be due to the wider frequency of genotypes or the use of different marker techniques. Meru et al, [38] determined the genetic distance in pupmkin genotypes between 0.08 and 0.76 in their study. A wider variation was detected in this study.…”