Study On DNA Fingerprinting Of Germplasm Resources Of Siraitia Grosvenorii

Siraitia grosvenorii is an endemic species of medicinal plant and economic crop to China, the rich germplasm resources of Siraitia grosvenorii are the material basis in breeding. In this study, in order to effectively identify and rational utilize the germplasm resources, and protect the intellectual property of new varieties, ISSR and RAPD markers were used to constructed the DNA fingerprinting and analyzed the genetic diversity of germplasm resources of Siraitia grosvenorii. The main results were as follows:1. This study used Bulked Segregate Analysis(BSA) to take the same amount of different individuals DNA to made up of varieties germplasm DNA pools. In 9 cultivated and 8 wild varieties germplasm DNA pools, 16 ISSR and 28 RAPD polymorphic primers were selected from 100 ISSR primers and 250 RAPD primers. Then made sure the characteristics bands in different varieties germplasm from all 54 cultivated samples and 36 wild samples of PCR electrophoretogram. Varieties germplasm DNA pools were used to constructed the DNA fingerprinting of cultivated and wild germplasm.2. 10 ISSR primers and 16 RAPD primers were selected to constructed ISSR and RAPD fingerprinting of cultivated and wild germplasm of Siraitia grosvenorii, then recorded the positions of characteristics bands and the names of identified germplasm in fingerprinting. The fingerprint identification tables of cultivated germplasm were created by ISSR primer 857 and RAPD primer group of S19 and S362, and the fingerprint identification tables of wild germplasm were created by ISSR primer 873 and RAPD primer S26, which will be used to quick and accurate identified the germplasm resources of Siraitia grosvenorii.3. 12 ISSR primers were applied in ISSR genetic diversity of germplasm resources of Siraitia grosvenorii.The total percentage of polymorphic bands was 77.59%, each germplasm percentage changed in 59% ~ 68%, wild germplasm was higher than cultivated germplasm in the percentage of polymorphic. The genetic similarity of every germplasm changed in 0.5107~0.9570, and the averaged of genetic similarity was 0.7376, which demonstrated that the genetic relationship in germplasm was close in the mass, but there was certain genetic variation. Compare cultivated germplasm with wild germplasm in the mass, there were lower genetic similarity and higher genetic variability of wild germplasm; genetic similarity of cultivated and wild male plant was lower than female, and there was higher genetic diversity of male. In hybrid combination between male and female, the hybrid combination between cultivated and wild was better than the hybrid combination between in cultivated germplasm, and in wild germplasm. The ISSR cluster analysis and principal coordinate analysis can be divided 17 germplasm of Siraitia grosvenorii into cultivated germplasm,wild germplasm and cultivated male Qingpi.4. 16 RAPD primers were applied in RAPD genetic diversity of germplasm resources of Siraitia grosvenorii. The total percentage of polymorphic bands was 79.52%, each germplasm percentage between 61.80%~66.99%, wild germplasm was little higher than cultivated germplasm in the percentage of polymorphic. The averaged of genetic similarity in germplasm was 0.7616, which demonstrated that the genetic relationship in germplasm was close in the mass. There was higher genetic diversity of wild germplasm than cultivated germplasm, and the genetic diversity of male was higher than female, the RAPD genetic diversity of germplasm resources in conformity with ISSR. The RAPD cluster analysis and principal coordinate analysis can be divided 17 germplasm of Siraitia grosvenorii into cultivated germplasm,wild germplasm and cultivated male Qingpi, and it consistent with the ISSR analysis. There were little different between ISSR and RAPD cluster analysis, in RAPD cluster analysis, the wild germplasm Donggua and wild male Hongmao were separated into other two groups from the wild germplasm.5. This study demonstrated that the DNA fingerprinting constructed by ISSR and RAPD markers were better, which can be used to quick and accurate identified the germplasm resources of Siraitia grosvenorii, There were high consistency result of two markers in genetic diversity of germplasm resources of Siraitia grosvenorii. The scattergram of principal coordinates analysis on germplasm were similar. The distribution of wild germplasm was looser than cultivated germplasm, which demonstrated that the genetic diversity of wild germplasm was higher than the cultivated germplasm. The principal coordinates analysis support cluster analysis. Two markers can effectively reflected the genetic variation and diversity information in the germplasm resources of Siraitia grosvenorii.