岛屿植物舟山新木姜子居群遗传多样性的RAPD分析

基于随机扩增多态 DNA(RAPD)方法分析了舟山群岛濒危植物舟山新木姜子 (N eolitsea sericea) 6个居群的遗传多样性及分化程度。 10条随机引物扩增出 84个可分析位点 ,多态位点百分比 (PPL)为 3 8.10 %。经 POPOGENE分析发现 ,舟山新木姜子居群平均水平的多态位点百分比 (PPL )为 2 3 .18% ,Nei' s基因多样度 (HE)为 0 .0 793 ,Shannon信息指数 (H )为 0 .12 0 1,与其它岛屿植物比较具有中等偏低水平的遗传多样性 ;岛屿各居群间遗传分化程度较高 (Gst=0 .3 646) ;地理距离与遗传距离之间具有显著相关性 (r=0 .7697,P=96.62 % ) ,岛屿隔离效应是导致居群间遗传分化的重要因素。结合居群遗传多样性及UPGMA聚类分析 ,推测普陀山岛舟山新木姜子部分个体可能为大猫岛迁入的后裔 ,而朱家尖岛舟山新木姜子则由人为移植自普陀山岛。基于舟山新木姜子的物种保护及资源利用 ,建议加强现有自然居群的就地保护 ,促进居群自然更新 ;建立种质资源库 ,收集不同岛屿的种源进行混合繁殖 ,促进基因交流 ;选育优良品系用于海岛植被恢复及园林观赏

Population genetic diversity of the insular plant Neolitsea sericea based on random amplified polymorphic DNA (RAPD)

The Zhoushan archipelago is the largest archipelago in China. It separated from the mainland about 9000 years ago due to rising sea level and climate change. Because of the long-term influences of human activities, forest vegetation on the larger islands was badly damaged and plant diversity reduced. The remaining plants are deserving of attention, especially the 21 endangered plant species distributed in the archipelago. Genetic diversity and genetic differentiation were examined in six populations of the insular endangered plant Neolitsea sericea in Zhoushan archipelago using random amplified polymorphic DNA (RAPD) markers. A total of 84 discernible loci were obtained for all populations using 10 primers, 38.10% of which were polymorphic (PPL=38.10%). As analyzed by POPOGENE, average percentage of polymorphic loci (PPL=23.18%), Nei's genetic diversity (H_E=0.0793) and Shannon's information index (H=0.1201) indicated that Neolitsea sericea had a lower level of genetic diversity than other insular plants. The high value of differentiation (Gst=0.3646) indicated that geographic isolation strongly influenced genetic differentiation among populations, and a significant correlation was found between genetic distance and geographic distance (r=0.7697,p=96.62%). The combined information from analyses of genetic diversity and UPGMA indicated that some individuals on Putu Island were immigrants from Damao Island, and that populations on Zhujiajian Island had been translocated from Putu Island by human activities. Management strategies were proposed for species conservation and resource utilization for Neolitsea sericea. These included (a) in situ protection from human disturbance to facilitate natural regeneration, and (b) construction of germplasm resources and cultivate plants collected from insular populations for use to enhance gene flow, and to select elite lines for vegetation restoration and gardening applications on islands.