Ge Xue-Jun, Yu Yan, Yuan Yong-Ming, Huang Hong-Wen, Yan Cheng
South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, P R China.
Ann Bot. 2005 Apr;95(5):843-51. doi: 10.1093/aob/mci089. Epub 2005 Feb 8.
The desert legume genus Ammopiptanthus comprises two currently endangered species, A. mongolicus and A. nanus. Genetic variability and genetic differentiation between the two species and within each species were examined.
Inter-simple sequence repeat (ISSR) marker data were obtained and analysed with respect to genetic diversity, structure and gene flow.
Despite the morphological similarity between A. mongolicus and A. nanus, the two species are genetically distinct from each other, indicated by 63 % species-specific bands. Low genetic variability was detected for both population level (Shannon indices of diversity Hpop = 0.106, percentage of polymorphic loci P = 18.55 % for A. mongolicus; Hpop = 0.070, P = 12.24 % for A. nanus) and species level (Hsp = 0.1832, P = 39.39 % for A. mongolicus; Hsp = 0.1026, P = 25.89 % for A. nanus). Moderate genetic differentiation was found based on different measures (AMOVA PhiST and Hickory B) in both A. mongolicus (0.3743-0.3744) and A. nanus (0.2162-0.2369).
The significant genetic difference between the two species might be due to a possible vicariant evolutionary event from a single common ancestor through the fragmentation of their common ancestor's range. Conservation strategies for these two endangered species are proposed.
沙漠豆科植物沙冬青属包含两种目前濒危的物种，蒙古沙冬青和矮沙冬青。对这两个物种之间以及每个物种内部的遗传变异性和遗传分化进行了研究。
获得了简单序列重复区间（ISSR）标记数据，并就遗传多样性、结构和基因流进行了分析。
尽管蒙古沙冬青和矮沙冬青在形态上相似，但两个物种在遗传上彼此不同，63%的物种特异性条带表明了这一点。在种群水平（蒙古沙冬青的香农多样性指数Hpop = 0.106，多态位点百分比P = 18.55%；矮沙冬青的Hpop = 0.070，P = 12.24%）和物种水平（蒙古沙冬青的Hsp = 0.1832，P = 39.39%；矮沙冬青的Hsp = 0.1026，P = 25.89%）均检测到低遗传变异性。基于不同测量方法（分子方差分析PhiST和希科里B），在蒙古沙冬青（0.3743 - 0.3744）和矮沙冬青（0.2162 - 0.2369）中均发现了中等程度的遗传分化。
这两个物种之间显著的遗传差异可能是由于从单一共同祖先通过其共同祖先分布范围的破碎化而发生的一次可能的替代进化事件所致。针对这两种濒危物种提出了保护策略。
