Genetic Diversity Analysis And Establishment Of Molecular Ids Of Some Apple Cultivars(Lines) In Yunnan

Apple is one of the delicious fruit trees,and apple industy is the main source of income in China.The accurate identification of apple germplasm resources is the prerequisite for the preservation and utilization of apple germplasm resources.Accurate identification of apple germplasm resources is a prerequisite for the preservation and utilization of germplasm resources.There are many apple varieties in production,but the origin of which is very confusion.Therefore,the identification of existing resources and varieties is extremely important in order to facilitate the accuracy of resource preservation and the effectiveness of resource utilization.In this study,72 apple varieties（lines）from Zhaotong,Yunnan were used as research materials,and genetic diversity analysis and molecular identification card of 72apple varieties were constructed,the main results very listed as follows:1.Determination the optimal SSR-PCR reaction system and primer screeningThe suitable SSR-PCR reaction solution for the apple varieties were DNA was 2.4ng/μL,primer was 0.2 umol/μL,Mg²⁺concentration was 2 umol/μL,dNTP concentration was0.1 umol/μL,and TopTaq concentration was 0.5 U/μL.And through agarose and polyacrylamide gel electrophoresis detection,it was found that 32 pairs of 108 SSR primers had amplified some sites using apple germplasm,and 28 pairs were polymorphic.2.Analysis of genetic diversity of 72 apple varieties（lines）Based on the SSR-PCR experiments,the average number of alleles（Na）,effective alleles（Ne）,diversity index（Ho）,Shannon index（I）and polymorphism index（P）of apple varieties were 4.4300,1.7619,0.3633,0.6336,0.0400,respectively.These genetic diversity indexes indicated that apple varieties were abundant in genetic diversity;UPGMA cluster analysis were designed,the result showed that the genetic similarity coefficient of 72 apple varieties varied from 0.470 to 1.000,and the average genetic similarity coefficient was 0.735.When the genetic similarity coefficient was about 0.646（L1）,72 apple germplasm resources were divided into three categories;and when the genetic similarity coefficient 0.700（L2）was used as the threshold,they were divided into 8 major groups.3.Molecular identification cards of different apple varieties were constructed using SSR markersIn this study,clear amplification hands using 17 pairs of primer were selected to distinguish 72 local apple varieties in Yunnan,and molecular ID cards were constructed based on the genotype of the fingerprint,using QR codes,providing the theoretical foundation for identifying apple germplasm resources.