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内蒙古荒漠区锦鸡儿遗传多样性分析

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

【Author in Chinese】 梁颖

【Supervisor】 杨九艳

【Author's Information】 内蒙古大学, 生态学, 2018, 硕士

【Abstract in Chinese】 内蒙古荒漠区作为亚洲中部荒漠区的一个重要组成部分,是锦鸡儿属植物的主要分布区域。因其气温高,降水少,辐射强等气候特点,在长期的进化历程中,植物在表型和基因等方面形成了适应和进化上的意义,使锦鸡儿植物在形态结构、生理生化功能、遗传特性等多方面成为荒漠植被的优势植物,本研究通过研究遗传结构来认识植物对环境的适应机制。为此,应用SSR(Simple Sequence Repeat)分子标记技术对分布于内蒙古荒漠地区9种锦鸡儿优势种:矮锦鸡儿(Caragana pygmaea(Linn)DC.)、狭叶锦鸡儿(C.stenophylla Pojark.)、中间锦鸡儿(C.intermedia Kuang et H.C.Fu)、柠条锦鸡儿(C.korshinskii Kom.)、短脚锦鸡儿(C.brachypoda Pojark.)、藏锦鸡儿(C.tibetica Kom.)、荒漠锦鸡儿(C.roborovskyi Kom.)、白皮锦鸡儿(C.leucophloea Pojark.)、鬼箭锦鸡儿(C.jubata(Pall.)Poir.)19个种群的遗传多样性进行研究,分析比较种间和种内的遗传结构和遗传分化,探讨其与土壤因子、气象因子的相关关系以及环境对形态分化的影响。主要结果如下:1)形态及土壤养分特征分析:柠条锦鸡儿的平均冠幅(42934.36 cm2)和平均株高(203.23 cm)显著高于其他8种锦鸡儿,而狭叶锦鸡儿和短脚锦鸡儿的平均株高(20.05 cm&25.67 cm)和平均冠幅(3387.51 cm2&1167.91 cm2)均处于较低水平,9种锦鸡儿的变异表现不同,狭叶锦鸡儿、中间锦鸡儿、短脚锦鸡儿株高和冠幅在种内差异显著(P<0.05);相关性分析表明,植物高度与有效积温存在显著相关关系(P<0.05),与10-20 cm土壤全磷有极显著的关系(P<0.001);冠幅与有效积温、0-10 cm土壤全磷有极显著的关系(P<0.001)。2)SSR遗传多样性分析:19个锦鸡儿居群的Shannon信息指数和Nei’s基因多样性指数分别为0.3047和0.1807;居群的遗传分化系数(GST)为0.4573,种群间基因流(Nm)为0.5935;无论在居群水平上,还是在种的水平上,都表现出较高的遗传多样性,但种间分布不均匀,从Shannon信息指数和Nei’s基因多样性指数来看,柠条锦鸡儿均为最高(0.4355和0.2816),白皮锦鸡儿均为最低(0.3259和0.2015),说明柠条锦鸡儿的遗传多样性最高,具有较高的生态适应性,白皮锦鸡儿的遗传多样性最低;9种锦鸡儿都具有丰富的遗传分化(GST>0.15),相比较而言狭叶锦鸡儿、短脚锦鸡儿和中间锦鸡儿的遗传分化程度较大,具有更强的环境适应能力;基因流Nm均大于1,意味着居群间基因交流频繁,可维持该物种的稳定性。3)遗传多样性与生态因子的相关性分析:19个锦鸡儿属居群的遗传距离与地理距离之间并无显著相关性,r=0.00173(p=0.5042>0.001);逐步回归分析显示,年平均气温显著的影响着遗传特征(P<0.05)。4)聚类分析表明:9种的锦鸡儿属植物能明显的区分开来;亲缘关系较近的种群聚在一起;同一物种内,地理距离相近的种群会优先聚类。

【Abstract】 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.

【Keywords in Chinese】 内蒙古荒漠区锦鸡儿属SSR遗传多样性
【Key words】 Inner Mongolia desert areaCaragana Fabr.SSRGenetic diversity
  • 【CLC code】Q943;Q948
  • 【Downloads】62
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