Construction Of Molecular Map For Melon(Cucumis Melo L.) DUS Testing And Genetic Diversity Analysis

The construction of melon DNA fingerprinting database is of important value in melon purity,identity testing and the protection of variety right, and the genetic diversity analysis of melon is of significance in heterotic group, germplasm innovation and variety breeding. SSR markers are considered to be the best markers.This study is to optimizethe system of PCR amplification reaction, explore the feasibility of multiplex PCR system on melon, aimd to improve identification efficiency and save time. On this basis, core primers were screened by 13 melon materials, then construct DNA fingerprinting database, analysis the genetic diversity of melon and purity identification of melon crossing combinations, main results were as follows,1.The optimal PCR amplification system was obtained by the gradient design of concentration of DNA, dNTPs, primer, Taq enzyme and Mg2+, and duplex SSR-PCR system was established of melon, and the amplification efficiency was improved two times.2.22 core primers were obtained form 174 SSR primers, and a total of 77 polymorphic loci was amplified in 13 melon materials, 2~4 polymorphic bands were detected by each primer, and the average was 3.5. And the average of polymorphism information contents was 0.806 with the range of 0.737~0.839. 18 core primers distributed on 10 chromosome of melon.3.Fingerprint codes of 52 melon materials were established, and were converted to two-dimensional coding completely, there were 7 groups of materials with the same fingerprint code, involving 23 materials. The fingerprint codes for each material in the remaining 29 meon materials were unique.4.The results of cluster analysis showed that the similarity coefficients was between 0.07~0.72 based on 20 morphological traits,and the average was 0.39.And 95 melon materials could be divided into nine group when the similarity coefficients greater than 0.07.The diversity of group ? to group ? was low, and the genetic diversity increased sequentially from group ?to group ?.5.The results of cluster analysis showed that the similarity coefficients between 0.55~1.00 based on 22 pairs of core primers,and the average was 0.78. And 95 materials could be divided into two group,and the two group can be divided into different subgroup according to different variants of melon.6. 74 primers were screened by 16 crossing combinations, and 10 primers were obtained which showed polymorphism and co-dominant, and 16 crossing combinations can be identified by these primers through the way of combination, and provided support for the protection of intellectual property rights and the practical application.