【作者】 高丽；

【导师】 杨波；

【作者基本信息】 中国科学院研究生院（武汉植物园） ， 植物学， 2006， 硕士

【摘要】 近年来，由于过度采挖和生境片断化，湖北野生春兰资源正面临着灭绝的危险。本文采用ISSR分子标记技术对湖北省内的11个春兰野生居群共325个个体的遗传多样性水平及居群遗传结构进行了研究。11个引物共扩增出127个位点，其中112个为多态位点，占88.19％。POPGENE分析结果表明：与其他兰科植物相比，春兰具有丰富的遗传变异（在物种水平上，H_e=0.2628，H_o=0.4037；在居群水平上，PPL=63.06％，H_e=0.1945，H_o=0.2958）。Nei’s遗传多样性分析和AMOVA分析表明，各居群间产生了一定程度的遗传分化(G_ST=0.2440，F_ST=0.2207)。居群间一定程度的遗传分化可能是由基因流障碍（N_m=0.8828）和对生境的人为破坏引起。UPGMA聚类分析可知，恩施地区的5个居群优先聚成一支，而大悟（DW）居群与其他居群分开单独聚为一支。Mantel检验结果表明居群间的地理距离和遗传距离之间没有显著相关性（r=0.25093，p=0.9704）。根据以上研究结果，我们提出如下保护措施：（1）来凤（LV）、京山（JS）、大悟（DW）居群现存个体尚多，遗传多样性损失不甚严重，因此以保护其所在的生境为基础，设立保护点进行就地保护是比较合适的保护策略；（2）毛坝（MB）和宣恩（XE）居群目前受破坏程度非常严重，所剩个体很少，遗传多样性较低，已经很难进行有效的就地保护。因此，对这两个居群应采用迁地保护的手段抢救目前尚存的个体。更多还原

【Abstract】 Wild Cymbidium goeringii （Orchidaceae） plants are becoming extinctive for over- harvesting and habitats fragmentation in Hubei Province recent years. The genetic diversity of 325 individuals from 11 populations in Hubei Province was investigated using inter-simple sequence repeat （ISSR） markers. As a result, 127 bands were amplified by 11 informative and reliable primers, of which 112 （PPL = 88.19%） were polymorphic loci. A relatively high level of genetic diversity were revealed: PPL=88.19%, H_e = 0.2628, H_o= 0.4037 （at species level）; PPL = 63.06%, H_e = 0.1945, H_o = 0.2958 （at population level）. A higher level of genetic differentiation was detected among populations (G_ST = 0.2440, F_ST = 0.2207) with Nei’s G_ST analysis and analysis of molecular variance （AMOVA）. Some differentiation may result from habitats fragmentation and barriers to gene flow. UPGMA cluster analysis indicated that five populations from Enshi region grouped together, whereas Dawu population clustered in a clade solely. The Mantel test showed that genetic distance was positively correlated with geographical distance. On the basis of these findings, the following conservation strategies are proposed: （1） In situ conservation will be suitable for Laifeng, Jingshan, and Dawu populations, because them possess sufficient genetic diversity. （2） In contrast, an ex situ strategy should be taken into consideration for Maoba and Xuanen populations, where only a few individuals left.更多还原