【作者】 张萍；

【导师】 董玉芝；

【作者基本信息】 新疆农业大学 ， 林木遗传育种， 2006， 硕士

【摘要】 白梭梭(Haloxylon persicum)和梭梭(Haloxylon ammodendron)是藜科梭梭属多年生小半乔木。它们在维持荒漠生态系统的结构与功能、防止土地沙漠化、改善小气候方面具有十分重要的作用。近年来,由于不合理地开发利用,大面积的天然梭梭林衰退甚至死亡。本研究利用ISSR分子标记技术,对中国新疆的白梭梭和梭梭居群的遗传多样性进行了研究。1.采用了11个ISSR引物。白梭梭4个居群的多态位点百分率为84.85%。不同居群多态性位点百分率在33.92%~40.35%之间;白梭梭的Shannon多样性指数0.3518,Nei遗传多样性指数为0.3482;白梭梭总的基因多样性为0.3488,居群内的基因多样性为0.1312,遗传分化系数为0.6238,基因流为0.3016;白梭梭梭梭居群遗传一致度的变化范围为0.6221~0.7239,遗传距离最小的为吐鲁番居群和乌苏居群;2.梭梭8个居群的多态位点百分率为89.23%。不同梭梭居群多态性位点百分率在23.42%~ 45.05%之间。梭梭的Shannon多样性指数为0.5060,Nei遗传多样性指数为0.3362。梭梭总的基因多样性为0.3357,群体内的基因多样性为0.1216,居群间遗传分化系数0.6378,基因流为0.2840。梭梭居群遗传一致度的变化范围从0.6414~0.7942,莫索湾和乌苏遗传距离较近。白梭梭与梭梭居群间均出现了一定的遗传分化;根据Nei’s遗传距离利用MEGA软件构建了居群的遗传关系UPGMA聚类图。根据分析结果,新疆白梭梭与梭梭居群都具有较高的遗传多样性,说明梭梭属植物并非由于遗传多样性的缺乏而致危,还受其它因素的制约。白梭梭和梭梭居群的保护首先要加强现有资源和生境的保护,其次需要加强人工繁育的力度。更多还原

【Abstract】 Haloxylon persicum and Haloxylon ammodendron were xerophytic desert shrub. As dominate desert plant, they played important role in the maintenance of the structure and function of the Desert Ecosystem. During the last few decades, Irraiional exploitation had resulted in the destruction of Haloxylon persicum and Haloxylon ammodendron vegetation and development of mobile sand dunes. The genetic relationship and genetic diversity of Haloxylon persicum and Haloxylon ammodendron in Xinjiang of China were studied by ISSR molecular marker technique.1. The percentage of polymorphic was 84.85% in four populations of Haloxylon persicum with 11 ISSR primers. The percentage of polymorphic loci shared a range of 33.92%~40.35%; Shannon index was 0.3518 and Nei’s index was 0.3482 of Haloxylon persicum; The genetic diversity based on Nei’s method, among Haloxylon persicum populations was 0.1312. The coefficient of gene differentiation was 0.6183. The estimate of gene flow is 0.3016. The percentage of genetic identity of Haloxylon persicum was between 0.6221~0.7239,the smallest was Tulufan population and Wusu population.2. The percentage of polymorphic was 89.23% in eight populations of Haloxylon ammodendron with 11 ISSR primers. The percentage of polymorphic loci shared a range of 23.42%~45.05%. The highest was Wusu population. Shannon index was 0.3518 and Nei’s index was 0.3482 of Haloxylon ammodendron. The genetic diversity based on Nei’s method, among Haloxylon ammodendron populations was 0.1216. The coefficient of gene differentiation was 0.6378. The estimate of gene flow is 0.2840. and The percentage of genetic identity of Haloxylon ammodendron was between 0.6414~0.7942, and the smallest was Mosuowan population and Wusu population.There all have higher genetic diversity in Haloxylon persicum and Haloxylon ammodendron. based on Nei’s genetic distance construct UPGMA tree between populations. Based on the results of the analysis, Haloxylon persicum and Haloxylon ammodendron populations have high genetic diversity. This imply that Haloxylon plants’s rare was not restrainted by the deficiency of genetic diversity, but also by others factors. It is proposed that the habitats of Haloxylon persicum and Haloxylon ammodendron should be protected. Meanwhile.numbers can be increased by artificial propagation.更多还原