Study On The Genetic Diversity Of Cucumber(Cucumis Sativus L.)Germplasm

Cucumber is an important worldwide vegetable. The genetic background of cucumbercultivars in production becomes narrower and narrower gradually because of natural geneticerosion and variety hybridization. Therefore, the study on genetic diversity of cucumberaccessions will be able to grow on its genetic distribution profoundly and offer the theoreticalhelp to cucumber breeding. In this study, the genetic diversity in cucumber accessions from different countries orregions was assessed by morphological marks and RAPD marks. The results showed: 20 primers producing qualified fragments were selected from 120 RAPD primers. 20informative RAPD primers were studied among 60 accessions. The results showed: most ofRAPD productions were polymorphic. A qualified PCR production could be acquired if wecould strictly control the PCR system and program. Therefore, the method of RAPD markerused to assessing the genetic diversity of cucumber germplasm is feasible and reliable. 50 cucumber accessions were clustered into four groups based on morphological marker.Cucumber accessions from different countries or regions can be divided into south Chinaecotypes and north China ecotypes. 60 accessions were clustered into eight groups based onRAPD marker, and the eighth group could be clustered into three litter groups again.According to the study, cucumber accessions from different countries could be clusteredproperly. This study on cluster analysis of cucumber will deepen the comprehension about thegenetic diversity of cucumber accessions and the genetic distance of different cucumbergermplasm. That will offer some instructive help to cucumber breeding. Candidate: Wang Zhikun Mayor:Vegetablebreeding Supervisor:Prof.QinZhiwei...