Research On Genetic Diversity Of Ornamental Peaches In Hunan Province

Peach is one of the oldest trees in China,the diversity of tree,the tree body beautiful,at the same time,the fruit is edible peach gum is also very good nutrition,with ornamental value,economic value and ecological benefits at the same time,it is very good varieties of trees.This article through to hunan changde area 38 species of ornamental peach phenological observation and ISSR molecular markers technology experiments,analyze its genetic diversity,reveals the different varieties of ornamental peach genetic relationship and genetic relationship,for the development of ornamental peach resources and protection provides a theoretical support.This is the results and methods are as follows:(?)Experiments using CTAB method and kit method to extract DNA,the purity of DNA extracted by the two methods all can meet the experimental requirements,but higher concentration of DNA extracted by CTAB method,the experiment takes longer,more cumbersome steps,early drug configuration and purchase also need more time.(?)The experiment using the orthogonal test method of Taq DNA polymerase,Mg2+ primer,template DNA,dDTPs,PCR concentration,annealing temperature,number of cycles that several aspects of the research,combined with mathematical and scientific analysis and careful observation of electrophoresis,obtained in the 25ul system,Taq DNA polymerase concentration for 0.4U,the template DNA was 10ng-80ng,dNTPs,0.20mmol ·L-1,0.3umol · L-1 primer concentration,the number of cycles for 30 times,and at the temperature of 49.3? for ISSR-PCR annealing system optimum reaction conditions.(?)The optimal system under the condition of the 100 primers screened,successfully screened 10(816,817,825,828,835,836,842,848,873,890)primers for ISSR-PCR amplification,a total of 102 bands were amplified with repetitive and clear.The polymorphic bands accounted for 85.3%,the number of each primer with polymorphic bands in the 4 to 12 range,the molecular weight was between 200?2500BP,indicating the genetic polymorphism of Ornamental Peach has very strong.(?)38 ornamental peach cultivars were divided into 5 groups,and diversity analysis of Ornamental Peach overall percentage of polymorphic loci(P)was 85.2%,the average Shannon information index(1)was 0.3568,Nei gene diversity index(H)was 0.2511 by cluster analysis,the 5 populations of genetic distance distribution between 0.0145 and 0.1367,the genetic identity between 0.8412 and 0.9536,it can be concluded that the generated mountain peach varieties group and Naoe cultivar group in the history of geographical distance should be relatively close,and the birth of distance broom peach group and longevity peach variety population genetic geographical distance.(?)NTsys2.1e of 38 Ornamental Peach Cultivars DNA sample clustering analysis,obtained between Zhaoshou white and Zhaoshou Ji genetic distance,white mountain and red purple Bi branches between the farthest genetic distance,also found that the ornamental peach branches according to clustering very obvious trend,but also ornamental flower type peach clustering standard.