Genetic Diversity Analysis Of Squash Germplasm Resource With RAPD

Squash, an important worldwide vegetable, is extremely variable of germplasm resource. The study on genetic diversity of squash accessions will favor for understanding better genetic diversity distribution profoundly and relationships of germplasm, and offering the theoretical help for collection, management and squash breeding.In the study, the genetic diversity in squash accessions from different countries or regions was assessed by random amplified DNAs(RAPDs).The results showed:26 primers produceing qualified fragments were screened from 260 random primers, RAPD markers by 26 informative primers were used to determine the frequence of DNA polymorphism in squash germplasms. A total of 255 bands were detected among 76 squash accessions from different countries and regions. The genetic diversity is rich. Of them 207(81.18%)bands were polymorphic. All accessions were clustered into three groups :Cucurbita moschata,Cucurbita maxima and Cucurbita pepo . According to the clusters, squash accessions could be clustered properly. Cucurbita moschata was the closest from Cucurbita maxima, Cucurbita moschata was closer from Cucurbita pepo.The clusters were greatly indentified with the origins.The results were consistent with morphological classification.All the results showed, the study on cluster analysis of squash will deepen the comprehension about thegenetic diversity of quash accessions and the genetic distance of different groups. The difference within cultivars is obvious.The genetic diversity of squash accessions is rich, which will offer some instructive help to squash breeding.