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Université de Mongolie-Intérieure (2018)

Genetic Diversity Analysis of Caragana Fabr. in Inner Mongolia Desert Area

梁颖;

Titre : Genetic Diversity Analysis of Caragana Fabr. in Inner Mongolia Desert Area

Auteur : 梁颖;

Grade : Master’s Theses 2018

Université : Université de Mongolie-Intérieure

Résumé
The Inner Mongolia desert area as an important part of the desert region of Central Asia,and is the main distribution area of Caragana Fabr.In the long-term evolutionary process,due to the high temperature,low precipitation,strong radiation and other climate features in desert areas,plants have evolved in terms of phenotypes and genes.Caragana Fabr,dominant plants of desert vegetation.This study uses the genetic structure to understand the adaptation mechanism of plants to the environment.For this purpose,the genetic diversity and genetic differentiation of 9 species of Caragana Fabr.distributed in the desert regions of Inner Mongolia,C.pygmaea(Linn)DC.、C.stenophylla Pojark.、C.intermedia Kuang et H.C.Fu、C.korshinskii Kom、C.brachypoda Pojark.、C.tibetica Kom、C.roborovskyi Kom.、C.leucophloea Pojark.and C.jubata(Pall.)Poir.,which were analyzed by SSR(Simple Sequence Repeat)markers.The aim of this study is to analysis and compare genetic structure and genetic differentiation within and between species,and investigate the relationship between genetic diversity with meteorological and soil factors to analysis and the effect of environment on genetic differentiation.The main results are as follows.1)The morphology and soil characteristics:The average crown(42934.36 cm2)and average height(203.23 cm)of C.korshinskii Kom.are significantly higher than those of other 8 species.The crown and height of C.stenophylla Pojark.and C.brachypoda Pojark.are at lower levels.There are differences in height and crown between the 9 Caragana Fabr.species.The height and crown of C.stenophylla Pojark.、C.intermedia Kuang et H.C.Fu、C.brachypoda Pojark.were significantly different within the species(P<0.05).Correlation analysis shows that there is a significant correlation between the height with effective accumulated temperature and soil total phosphorus of 10-20 cm(P<0.05).Moreover,the crown of species with effective accumulated temperature and soil total phosphorus of 0-10 cm have significant correlation(P<0.001).2)SSR analysis of genetic diversity:The total Nei’s gene diversity index and the Shannon’s information index of the 19 Caragana Fabr.populations is 0.1807 and 0.3047.Genetic differentiation is 0.4573,and the gene flow is 0.5935.Both at the population level and at the species level,Caragana Fabr.shows high genetic diversity.The Shannon information index and Nei’s genetic diversity index of the C.korshinskii Kom.is the highest(0.4355 and 0.2816),and the C.leucophloea Pojark.is the lowest(0.3259 and 0.2015).It shows that C.korshinskii Kom.has the highest genetic diversity and high ecological adaptability.The C.leucophloea Pojark.is on the contrary.9 species of Caragana Fabr.are rich in genetic differentiation(GST>0.15).C.stenophylla Pojark、C.brachypoda Pojark and C.intermedia Kuang et H.C.Fu are more genetically differentiated and have stronger environmental adaptability.Nm>1,which means frequent gene exchange among populations and can maintain the stability of the species.3)Analysis of correlation between genetic diversity and ecological factors:There is no significant correlation between the genetic distance and geographical distance of 19 Caragana Fabr.populations.r=0.00173(P=0.5042>0.001).In stepwise regression analysis,annual mean temperature significantly affects genetic characteristics(P<0.05).4)Cluster analysis results:9 species of Caragana Fabr.clearly distinguish.Closely related populations come together.Within the same species,populations with similar geographical distances will also be clustered together

Mots clés : Inner Mongolia desert area; Caragana Fabr.; SSR; Genetic diversity;

Présentation (CNKI)

Page publiée le 16 mai 2019