神农架山体对濒危植物连香树遗传结构影响的研究  

Population Genetic Structure and Variation of Endangered Cercidiphyllum japonicumin Shennongjia Area: The Mountain Barrier to Gene Flow

作　　者：袁珊[1,2] 孟爱平[1] 李建强[1] 王恒昌[1] 

机构地区：[1]中国科学院武汉植物园植物种质创新与特色农业重点实验室,武汉430074 [2]中国科学院研究生院,北京100049

出　　处：《植物科学学报》2012年第4期358-365,共8页Plant Science Journal

基　　金：中国科学院知识创新工程重要方向项目(KSCX2-YW-Z-0939);国家自然科学基金项目(31070191;30121003)

摘　　要：山体屏障能阻断植物连续的生境,干扰居群的基因交流,从而影响植物居群的遗传结构。本研究应用AFLP标记探讨神农架地区南北坡4条河岸带分布的连香树4个居群的遗传多样性水平,以及山体隔离对居群遗传结构和基因流的影响。结果显示连香树居群水平的Nei’s基因多样性(h)和Shannon信息指数(I)分别为0.116和0.173,遗传多样性水平相对较高。在遗传结构方面,邻接树(NJ)和主坐标分析的结果清晰地将南北坡分开,从居群和个体上都分成两组。并且STRUCTURE的结果显示基因流在同坡向的居群间比不同坡向的居群间要大。这些表明神农架山体可能对连香树居群的基因交流产生了一定的限制作用。神农架南北坡居群间的分化程度较低(FST为0.075),推测与连香树自身有较强的种子散布和花粉传播能力有关。本研究结果表明,神农架山体及相关的生态因子可能对连香树居群的基因交流产生了限制作用。Mountain barriers was expected to interrupt habitats and have significant effects on the genetic structure, genetic biodiversity, and gene flow of plants. Using AFLP markers, we tested the genetic variation and differentiation of four populations of Cercidiphyllum japonicum Sieb. et Zucc. （Cercidiphyllaceae） along four riparian rivers in the northern and southern slopes of the Shennongjia region. The effect of the Shennongjia Mountain as a natural barrier to genetic structure and gene flow of the species was investigated. The Nei＇s gene diversity （h） and Shannon index （/） were 0.116 and 0.173 ,respectively. Despite the low genetic differentiation between the two slopes （ FST = 0. 075） ,the Neighbor-Joining Tree（NJ） and PCA data divided the four populations into two clusters corresponding to the northern and southern slopes. STRUCTURE analysis showed that the gene flow between populations within the same slope was higher than those in different slopes. Our results suggested that large mountains may have served as physical barriers to gene flow between plant populations. The low level of genetic differentiation of populations between the southern and northern slope may have resulted from the internal characters of long distance pollen and seed dispersal ability of the species. Our results suggested that large mountain may have served as physical barriers to gene flow between plant populations.

关 键 词：神农架 连香树 扩增片段长度多态性 山体隔离 基因流 遗传结构 

分 类 号：Q948[生物学—植物学]