青藏高原东缘中国沙棘的克隆多样性及克隆结构

 应用随机扩增多态性ＤＮＡ 标记（ＲＡＰＤ ｍａｒｋｅｒｓ）对青藏高原东缘中国沙棘的克隆结构、克隆多样性进行了初步的探讨。结果表明，１）１４条ＲＡＰＤ 引物在８个中国沙棘居群共１８４个样本中平均形成５５．７５种条带，平均有１５．１３种条带在居群内表现出多态性，平均多态条带百分率为２７．６４％；鉴别出２６种基因型，平均每基株形成３．４个分株；２）与应用ＤＮＡ 分子标记研究的其他克隆繁殖能力较强的植物相比，中国沙棘的克隆多样性水平偏低，Ｓｉｍｐｓｏｎ’ｓ多样性指数（Ｄ）平均值为０．８５；Ｆａｇｅｒ’ｓ均匀度指数（Ｅ）平均值为０．８７；３）克隆结构分析表明，中国沙棘每克隆内分株间的平均距离为１．７５ｍ，克隆繁殖的生长型主要为游击型，并且在居群内存在以某一优势基株为主的克隆分布方式；４）居群的定居时间、生境及群落结构等对中国沙棘的克隆多样性有一定影响。

The clonal diversity and structure of Hippophae rhamnoides ssp. sinensis in eastern Qinghai-Tibet Plateau in China

RAPD(random amplified polymorphic DNA) marker was used to detect clonal structure and diversity of Hippophae rhamnoides ssp.sinensis in eastern Qinghai-Tibet Plateau in China and analyze the possibility relationships between clonal diversity and its influencing effects.Our objectives were to examine the adaptive strategies of alpine plants to varied environments and establish a foundation for understanding reproduction and distribution of clonal plants.We selected 14 random primers for amplification and found average 55.75 repetitive loci with average 15.13 polymorphic loci(total average percentage of polymorphic loci was 27.64%).We differentiated 26 RAPD genotypes or clones among the 184 plants sampled,which formed 89 ramets by clonal growth.Features of size and shape of H.rhamnoides were small with only 3.4 ramets per gemets and 1.75 m between neighbouring ramets on average.Mean Simpson’s index was 0.85,and average E was 0.87,slightly lower than the plants which application of DNA molecular markers.Therefore,the H.rhamnoides populations growing in eastern Qinghai-Tibet Plateau have high capability of clonal growth.The formations of H.rhamnoides are guerill type and expand based on some dominant genets in populations,these distribution pattern increase the adaptation ability to the altiplano environment.The colonisation time,habitats and community composition have to a certain degree affected the clonal diversity of H.rhamnoides populations.