The Analysis Of Genetic Diversity Of Castanea Henryi By Using Molecular Marker Of SRAP

Castanea henryi belongs to Fagaceae chestnut, it is an important woody grain species in China.In the south of the Yangtze river,there are rich resources of Castanea henryi,and it has wide range of natural distribution and various types,but most of the resources is wild and the genetic background is complex.In order to fully exploit and use the wild germplasm of Castanea henryi, value the existing germplasm resources scientifically and reasonably, the paper using the method of SRAP molecular marker, taking 23 varieties of Castanea henryi and 17 populations resources of wild Castanea henryi in 5 provinces,which is Hunan、Zhejiang、Sichuan Guizhou、Fujian,as materials,we have made the research on genetic diversity.The purpose is to provide a evidence for genetic background analysis and germplasm innovation.The main conclusions are as follows:1、The SRAP-PCR amplification conditions suitable for Castanea henryi is established:in 20 μL reaction system,containing 40 ng template DNA,1.8 mmol/L Mg2+,280 μmol/L dNTP,2.0 U Taq DNA polymerase,0.6 umol/L primer.2、Selected the primer combinations which are suitable for the analysis of genetic diversity of Castanea henryi.Randomly selected 10 templates,and then using the 10 templates to select 15 primer combinations,which have clear、good stability and high polymorphism bands,from 100 primer combinations.The 15 primer combinations are: Eml-Me2、Em1-Me3、Em2-Me1、Em2-Me2、Em2-Me3、Em3-Me2、Em3-Me5、 Em5-Me2、Em7-Me1、Em7-Me3、Em9-Me7、Em9-Me9、Em9-Me10、Em10-Me6、 Em10-Me10.3、The genetic diversity analysis of 17 wild Castanea henryi populations indicates that wild Castanea henryi has high genetic diversity and it is an important source of germplasm innovation.By using the 15 primer conbinations to make a PCR amplification for 221 samples of 17 wild Castanea henryi populations, that amplified a total of 221 loci,the average number of polymorphic loci is 155.06,the genetic diversity is 70.16%.The number of total genetic diversity index、genetic diversity index、Nei’s genetic diversity index and Shannon’s information are 0.3636、0.2466、0.2460、0.3677, it shows that wild Castanea henryi population has high genetic diversity.And the polymorphism rate of HS population is the highest,which is 85.07%;The polymorphism rate of JS population is the second,which is 83.26%,that means HS、JS populations have the richest genetic diversity in Hunan province.The genetic differentiation coefficient among populations is 0.3217, estimate of gene flow is 1.0541,that means there are 67.83% of genetic variation within population in kind of level,and the gene flow is frequent.UPGMA indicates that XJ and HS population had the closest relationship with the maximum genetic similarity;GZ and YT population had the farthest relationship with the minimum genetic similarity.4、The genetic diversity analysis of 23 varieties of Castanea henryi:By using the 15 primer conbinations to make a PCR amplification for 23 varieties of Castanea henryi,the fragment size mainly between 150bp and 2500bp,and amplified a total of 221 loci, polymorphic loci is 197, the percentage of polymorphic loci is 89.14%.It means Castanea henryi species have high genetic diversity.The genetic similarity coefficient is between 0.66 and 0.85.In the genetic similarity coefficient of 0.66,Dajianzui was one class,the rest were the second category.It means there is a big difference between Dajianzui and others.In the largest genetic similarity,Huali2 and Tiezhui are clustered into one category,means they had the closest relationship with the minimum genetic diversity.And in order to provide a reference for rapid identification of Castanea henryi varieties,we builded a SRAP digital fingerprint for the 23 varieties of Castanea henryi by using 4 primer conbinations,which are Eml-Me2、Em2-Me1、 Em2-Me2 and Em2-Me3.