Genetic Diversity Of Tea Culivars And 70 New Strains From Sichuan And Chongqing Region

Sichuan and Chongqing area is one of the origin of tea plants,with a long history of tea production and rich resources,it is the main tea producing area in China.In 15 linkage groups of the SSR distribution for an average of 30 markers used in this experiment,with 12 other province of tea cultivars as the control,40 tea cultivars and 70 new strains of Sichuan and Chongqing area has been approved,which were analyzed the genetic diversity and relationship;and according to the genotype of SSR markers,selected 9 core primers for fingerprinting tea cultivars.In order to identify the genetic diversity of the main tea cultivars and breeding materials in Sichuan Province,the differences of polymorphisms and heterozygosity in different periods were analyzed,and the basis for the registration of new cultivars was provided.The main results are as follows:1.30 SSR makers with polymorphic and easily statistical were selected from the published genetic linkage map.The number of alleles(NA)per pair of primers was 4~8,genotypes(NG)was 6~29,effective alleles(NE)was between 1.939~5.966,the average was 3.491,and the Polymorphism information content(PIC)of primers was high,with an average of 0.681.2.By using 30 SSR primers,genetic diversity analysis of Sichuan tea variety resources and relationship,30 loci were observed 159 alleles,Shannon polymorphism index(I)with an average of 1.389,Nei "s genetic diversity(H)averaged 0.699,the average heterozygosity(Ho)was 0.630.according to the time of tea cultivar's release,The results show that before 2005 and tea cultivars of Shannon diversity index(I),Nei's genetic diversity(H)and observed heterozygosity(Ho)was higher than that in 2005 after the breeding of tea cultivar;reflects the after 2005 single breeding method of tea cultivars so that the level of genetic diversity of cultivars decreased in Sichuan and chongqing.At the same time,the heterozygosity,Shannon diversity index and Nei's genetic diversity of the new strains are also lower than the tea cultivars,indicating that this state is still continuing.The cluster analysis divides the 110 parts of Sichuan and Chongqing into four groups,clustering results were mainly related to the genetic background of the material.3.DNA fingerprinting technology is a simple and rapid method,which is suitable for tea cultivars identification.Using the above 30 pairs of SSR primers to identify the tested materials,the results showed that 122 tested materials had different genotypes,and the highest similarity between the two materials and 8 pairs of primers were different,indicating that the approved varieties and 70 new lines were specific at the level of DNA,providing a basis for the registration of new varieties of tea trees.Based on the clear degree,power of discrimination(PD),Effective number of allele(NE)and Polymorphism information content(PIC)of the amplified bands of the 30 pairs of primers,9 pairs of core primers were screened.These 9 pairs of core primers have ability to identify high probability theory,any of the two materials may be confused for 6 ×10-10,the probability of the full sib family may confuse the 2.4×10-4;DNA fingerprint of Sichuan and Chongqing 40 tea cultivars and 70 new strains was constructed by the 9 pairs of core primers.which provided a molecular level evidence for the identification of tea cultivars and the application and protection of cultivar rights.In order to further strengthen the study of the germplasm resources of tea varieties in Sichuan and Chongqing,on the basis of studying the genetic diversity of tea varieties and new strains in Sichuan and Chongqing,it is more necessary to carry out excellent quality resources and important functional genes to improve the utilization efficiency of resources and accelerate the process of tea breeding.At the same time,in view of the declining trend of the genetic diversity of the tested materials,in order to improve the genetic diversity of the varieties(lines)of the Sichuan and Chongqing tea plants,we should change the single breeding method(mainly using the system breeding method),improve the means and level of breeding,and use the breeding methods such as cross breeding,radiation breeding and so on.In order to improve the breeding level.