濒危物种裂叶沙参及其近缘广布种泡沙参的遗传多样性研究

Studies of Morphological and Allozyme Variation of the Endangered Adenophora lobophylla and Its Widespread Congener A. potaninii

根据对12个形态性状的统计分析和10个基因位点的等位酶检测，探讨了濒危植物裂叶沙参及其近缘广布种泡沙参的遗传多样性水平。对3个裂叶沙参和6个泡沙参天然群体的遗传分析表明，两种沙参属植物均具有很高的遗传变异水平，这种变异性既体现在形态学水平上，也体现在酶位点水平上。在2个茎叶形状以及10个花果和种子形状上，濒危种裂叶沙参的变异性均与广布种相当；同样，根据7个酶系统10个等位酶位点的度量，裂叶沙参群体的平均变异水平（P＝0．60，A＝187，H＝0．180）也与广布的泡沙参（P＝0．60，A＝1．82，H＝0．193）相当。结果表明，濒危种裂叶沙参并未表现出遗传变异性的下降。结合生态学研究资料表明，导致裂叶沙参濒危的主要原因是生态学因子，故生境保护对裂叶沙参的生存和发展是至关重要的。

Genetic diversity in the endangered Adenophora lobophylla and its widespread congener, A potaninii was investigated based on 12 morphological characters and 10allozyme loci. We measured considerably high levels of genetic variability in both the endangered and the widespread species. The endangered A. lobophylla maintains comparable high level of genetic diversity to that of A. potaninii at the morphological characters surveyed. Similarly, the allozyme variation in A. lobphylla(P=0.60, A=1.87,H=0.180) is almost the same as that found in A potaninii (P=0.60, A=0.82, H=0.193).The present study indicates clearly that the endangered A lobophlylla is not genetically depauperate. Combined with other lines of evidence, we hypothesize that A. lobophylla has become endangered for ecological and stochastic reasons. Consequently,habitat protection is of particular importance for conserving this endangered species.