珠芽蓼(Polygonum viviparum)是青藏高原东缘广泛分布的克隆植物，具有有性和无性（根状茎和珠芽）两种生殖方式。该研究采用RAPD技术对分布于不同海拔的珠芽蓼7个自然种群进行了克隆结构和克隆多样性（是单克隆种群还是多克隆种群）以及克隆多样性与海拔因子之间的相关性研究，为了解高山克隆植物对环境的适应性策略及揭示克隆植物的繁殖和分布特点提供科学依据。研究结果表明：1）采用13条RAPD引物对珠芽蓼7个种群共140个样本进行扩增分析，共扩增到117个位点，其中多态性位点84个，多态位点百分率PPL 达到 71.79％，检测到43个基因型，且全部为局限型基因型；2）与Ellstrand和Roose(1987)总结的克隆植物的克隆多样性平均值相比（PD=0.17，D=0.62），珠芽蓼种群克隆多样性水平稍高，Simpson指数平均为0. 639，基因型比率PD平均为0.307；3）克隆结构分析表明，珠芽蓼种群内克隆之间的镶嵌明显，这可能与珠芽蓼过渡型的克隆构型有关。研究中珠芽蓼种群的构型有游击型、密集型以及这两者之间的过渡类型；4）采用SPSS软件对珠芽蓼种群的克隆多样性与海拔高度进行相关性分析，结果显示它们之间并无明显的相关性。
Aims Polygonum viviparum, which is widely distributed in eastern Qinghai-Tibet Plateau in China, is a clonal plant species with two modes of reproduction, clonal propagation by below-ground rhizomes and bulbils and sexual by seeds. This study investigated clonal structure and diversity (monoclonal or multiclonal population) and the relationship between clonal diversity and the altitude. Our objective was to examine the adaptive strategy of alpine plants to varied environments and establish a foundation for understanding reproduction and distribution of clonal plants.
Methods We selected seven populations in eastern Qinghai-Tibet Plateau along an altitudinal gradient and sampled 20 individuals in each population with at least 1 m between individuals to avoid individuals from the same clone. We employed random amplified polymorphic DNA (RAPD) technology for studying clonal structure and diversity and analyzed the relationship between clonal diversity and altitude by SPSS software.
Important findings We selected 13 random primers for amplification and found 117 repetitive loci with 84 polymorphic loci (total average percentage of polymorphic loci was 71.79%). We differentiated 43 RAPD genotypes among the 140 plants sampled. Mean Simpson’s index was 0.639, and mean PD was 0.307, slightly higher than the mean of Ellstrand (PD=0.17, D=0.62). There was a clear mosaic among P. viviparum clones, probably because of diverse clonal structure. The formations of P. viviparum populations included guerilla, phalanx and a transitional type. Clonal diversity was independent of altitude.