Development of 19 transferable Cucurbita pepo EST-SSR markers for the study of population structure and genetic diversity in pumpkin (Cucurbita Moschata)

摘要

Cucurbita moschata is an economically important species worldwide, but little is known about its genic and genomic information. Few molecular markers have been developed for C. moschata so far, which is not sufficient for breeding programs. The aim of this study was to examine the feasibility of development EST-SSR markers from Cucurbita pepo to C. moschata and to evaluate their potential for genetic analysis in C. moschata cultivars. Eighty-two C. pepo EST-SSRs were tested against 29 C. moschata cultivars from different geographical origin in China. As a result, a high proportion (84.14%) of markers was transferable to C. moschata. From them, nineteen markers exhibited polymorphism. A total of 53 alleles were identified with an average of 2.789 alleles per locus in all the tested samples. The polymorphic information content (PIC), the observed heterozygosity (HO), the expected heterozygosity (HE), and the Shannon’s information index (I) were estimated to average 0.393, 0.125, 0.478, and 0.760, respectively. Population structure, principal coordinates and phylogenetic analysis all revealed that these 29 C. moschata cultivars tended to group into two subpopulations, which was related to fruit shape rather than geographic origin. Moreover, every subpopulation possessed its own population-specific alleles. This is the first report describing the development of transferable EST-SSR markers in C. moschata and their application to genetic analysis, which will offer an approach for future marker development and marker-assisted breeding in C. moschata.