The ISSR Genetic Diversity Analysis On The Caryopteris Mongolica An Endemic Plant In Mongolian Plateau

This thesis applies the ISSR molecular marker method to conduct the genetic diversity analysis on the Caryopteris mongolica natural population from 5 different regions of Huhhot,Shanxi Province,Wuhai,Saihan,and explores the level of its genetic diversity as well as the genetic structure with the aim to provide molecular basis for the genetic diversity protection,and provide the theoretical basis to make full use of it and formulate the scientific and effective protection measures.1.This research adopts the single factor experimental design method,taking the DNA from Caryopteris mongolica genome as the amplification template of ISSR-PCR,was used to establish and optimize the amplification reaction system of ISSR adaptable to Caryopteris mongolica:in the reaction system of total volume of 20?L,containing10×PCR buffer12.5ul,2mmol/LMg²⁺,1.5UTaq DNA polymerase,1.5mmol/LdNTP,2mol/L primers,and 15ng template DNA.The temperature profile used for ISSR was95?for 5min;92?for 1min;52?for 1min and 72?for 2min;40cycles;and was terminated with a 10 min DNA extension step at 72?;stored at 4?.2.Fifteen stable and reproducible primers were screened from 100 ISSR primer sequences published by University of Columbia,Canada.And a total of 189 bandswere amplified with 181 Polymorphic bands.The amplified fragments were between 200-1000bp.Among these,the amplified polymorphism ratio of the primer 807,813,835,841,844,880,810,895 and 892was 100%.It is suggested that the Caryopteris mongolica is more polymorphic.The percentage of polymorphic at population level ranged from 50%?Wuhai population?to 84.72%?Shanxi Province1group population?.3.The genetic diversity of the Caryopteris mongolica was analyzed by POPGENE32 software and the corresponding index value was obtained as follows:at the species level of the Caryopteris mongolica tested material,the number of alleles?Na?was 1.6722;the effective number of alleles?Ne?was 1.3641;the genetic diversity of Nei?H?was 0.2145;the Shannon polymorphism information index?I?was 0.3226.The Nei's diversity index and Shannon information index of different populations showed the same trend,namely,that is Shanxi Province 1 group population>Huhhot population>Shanxi Province 2 group population>Saihan population>Wuhai population.The above data indicated that the diversity level of the whole transmission of the Caryopteris mongolica was very high.4.The total genetic diversity?Ht?of the Caryopteris mongolica was 0.2715,the genetic diversity?Hs?within population was 0.2145,and the coefficient of gene differentiation?Gst?was 0.2102,which indicated that 21.02%of the genetic variation within the population of the Caryopteris mongolica exsited among populations,78.98%of the genetic variation came from within the population,and the genetic differentiation within populations was much higher than that among populations.Except that,the Nm level of the gene flow among Caryopteris mongolica populations obtained from the genetic differentiation coefficient can be expressed as follows:Nm level=1.8790,indicating that there has lower gene flow in different populations of the Caryopteris mongolica.5.The cluster analysis map of five populations was obtained by UPGMA method.The populations of the Caryopteris mongolica in five regions were divided into two populations.Among them,3species,including Huhhot population,Saihan population,Wuhai population were clustered into a class,while Shanxi Province 1group population and Shanxi Province 2 group population clustered into a class independently.The results displayed a certain geographical distribution.