冷蒿种群在放牧干扰下遗传多样性的变化  

Changes of the genetic diversity of Aremisia frigida population under the disturbance of grazing

作　　者：王静[1] 杨持[1] 尹俊 王铁娟[1] 刘朋涛[1] 

机构地区：[1]内蒙古大学生态与环境科学系 [2]内蒙古高校动物遗传育种重点实验室,呼和浩特010018

出　　处：《生态学报》2004年第11期2465-2471,共7页Acta Ecologica Sinica

基　　金：国家重点基础研究发展规划资助项目 ( G2 0 0 0 0 4870 4) ;国家自然科学基金资助项目 ( 3 0 3 60 0 18) ;内蒙古教育厅科学研究资助项目( NJ0 2 0 96)~~

摘　　要：通过随机扩增多态性 DNA(RAPD)方法检测了放牧干扰下冷蒿种群遗传多样性的变化。 17条 (组 )引物进行 RAPD分析 ,扩增共产生 2 5 4条带 ,其中 2 4 0条为多态性带 ,多态位点百分率达 94 .4 9%。随着放牧强度的增加 ,冷蒿种群多态位点百分数 ,Nei遗传多样性指数、Shannon信息指数均下降 ,种群内个体平均遗传一致度增加。放牧梯度上 4个冷蒿种群 H t=0 .2 116 ,Hs=0 .170 0 ,Dst=0 .0 4 16 ,种群间基因分化系数 Gst=0 .196 5 ,基因流 N*m=2 .0 4 5 1;同时随着放牧强度的增加 ,种群间的 Dst、Gst增加 ,N*m 降低。说明放牧限制了种群间的基因交流 ,使种群发生遗传分化。放牧梯度上的 4个冷蒿种群的遗传距离很小 ,但是随着放牧强度的增加 ,遗传距离在缓慢的增加 ,种群间的遗传一致度降低。根据遗传距离所构建的 U PGMA聚类图中冷蒿 4个种群随着牧压的增加 ,逐级聚在一起。July, the experimental plant materials Leng Hao (Artemisia frigida) were collected from a series of grazing gradient of Leymus chinensis steppe near the Inner Mongolia Grassland Ecosystem Research Station, The Chinese Academy of Science. The location is 43 °33′ N and 116°40′ E. The altitudes range from 1200 to 1250m. The mean annual temperature is -0.4℃. The annual precipitation is 350mm. The evaporation is four times as much as precipitation. The zonal soil is chestnut soil. Four grazing pressure gradients (sampling site) established on a section from herdsmen residence to the research station (enclosed for 20 years), that were no grazing (CK enclosure site), light grazing(LG), moderate grazing(MG) and heavy grazing (HG). Twenty samples were taken randomly from each grazing gradient, and each sample consisted of younger leaves of one stem of A. frigida. Changes of genetic diversity of Artemisa frigida Population under different disturbance of grazing were studied by the Random Amplified Polymorphic DNA(RAPD). 17 primers were used and produced 254 bands in total, 240 bands out of those were polymorphic.The percentage of polymorphic loci was 94.49%. With the increase of grazing intensities, the percentage of polymorphic loci of A.frigida population decreased. The polymorphic loci of CK population was 214, while that of HG population was 132. Total Nei's genetic diversity index of four population was 0.2119. Shannon information index of four population was 0.3448. With the increase of grazing intensities, Nei's genetic diversity index and Shannon information index decreased. This indicated disturbance of grazing decreased the genetic diversity. Total genetic diversity (Ht) of four A. frigida populations under different grazing intensities was 0.2116. Genetic diversity within four populations (H_S) was 0.1700. Genetic diversity among four populations (D_(ST)) was 0.0416. Genetic differentiation coefficient among populations(G_(ST)) was 0.1965, Gene flow (N~*_m) was 2.0451. Meanwhile, with the increase

关 键 词：冷蒿种群 遗传多样性 遗传分化 RAPD 

分 类 号：S54[农业科学—作物学]