| Persimmon belongs to a kind of species of Diospyros L. in Ebenaceae. The persimmon resources in China are very rich, the varieties are over one thousand. These rich resources guarantee the plenty of materials for the genetic improvement and new speicies breeding. However, due to the limitation of research means and facilities, people still lack of comprehensive understanding about persimmon germplasm resources. The background of most Chinese persimmon germplasm was not clear, in order to research and use them better,we must find a efficient tool to evaluate these germlasm.In recent years, molecular markers which are used to reveal the different of DNA levels were widely used. They include two categories: the first is RFLP which is not based on the PCR; the second is RAPD,AFLP,SSR and SNP which are based on PCR. With the simple and stable characteristics, SSR is widely used in breeding,cultivar identification and related analysis and the research about germplasm origination. Because of the abundant polymorphism and co-dominant features, SSR if widely applied in the construction of genetic maps with other molecular markers, such as arabidopsis, tomato, corn, cabbage, capsicum and honeydew. At present, SSR has been applied in many research relating to plant genetic diversity. Molecular markers in the research of persimmon are still limited. The application of molecular markers, such as SSR and ISSR has just began in persimmon. So, there is not plenty of persimmon resources to be choosen. In this study, seven species of persimmon and persimmon varieties of germplasm resources are taken as experimental materials, the aim is to use SSR molecular marker methods to analyze their genetic diversity and relationship at the molecular level, to help people use these germplasm resources more effectively. The main results are as follows:1.The genomic DNA of persimmon was extracted by a modified CTAB method.Besides, it is indicated that better quality of DNA can be extracted from bud and tender leaves comparing fruits,old leaves,twigs and other different materials;2. 17 pairs of primers were selected from 30 ones of SSR in 48 different materials.,which could produce stable and polymorphic bands;3.Optimal SSR system in persimmon was established. In a total volume of 20μL PCR system, it contains 20ng template DNA , 1 U TaKaLa Taq,1×buffer, 1. 5 mM MgCl2, 0. 2 mM dNTP, 10 pmol SSR Primer. The PCR reaction condition was 94℃initial denaturation4 min; 94℃denaturation 1min, 60℃annealing1 min, 72℃extension 2 min 35 cycles; 72℃final extension 5 min;4.The establishment of a PCR product of silver staining method, denaturing polyacrylamide gel at 1600 V the voltage electrophoresis and stained with silver nitrate, anhydrous sodium carbonate color ;5.By NTSYS-pc2.10e software we had the cluster analysis sorts with the SSR data ,obtained the genetic map of persimmon germplasm resources, analysised the genetic relationships among species, and compared field analysis. The 48 Persimmon materials were divided into 4 categories, each of them included the same species of persimmon.The result shows SSR markers distinguishing persimmon germplasm is feasible, is an effective means to researching the genetic diversity of germplasm resources of persimmon .
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