阿尔卑斯山黄花茅(Anthoxanthum alpinum)沿海拔梯度的基因频率分布

在瑞士阿尔卑斯山的2个定点样地，黄花茅从森林线（海拔1700 m）到山顶（海拔2830 m）呈连续分布。在海拔梯度样带的最高和最低定样场所间的垂直距离差不多为1000 m，但2个定样场所间相距仅仅1.4 km。在所研究的3个海拔梯度样带中，3个同工酶位点（Px_1, Got_2和 Mdh_1）被观察到有统计意义的倾群变异。研究结果显示：沿海拔梯度样带的亚居群间的基因流可能太弱不足以克服自然选择的影响，后者促使对局部环境的适应。在这种情况下，温度因子至少可能作为一种主要的自然选择力起作用。

Gene frequency distributions of Anthoxanthum alpinum along the altitudinal gradients in Swiss Alps

Anthoxanthum alpinum has a continuous distributio n from the treeline (1700 m) to the summit ridges (2830 m) in Arpette and Belalp of Valais, Swiss Alps. The highest and lowest sites of the transect differ by almost 1000 m in elevation, but only an average of 1.4 km apart. A significant clinal variation was observed at three allozyme loci (Px_1, Got_2 and Mdh_1) on all three transects. It suggests that gene flow among sub_populations may be t oo weak to overcome the effects of natural selection in favor of adaptations to local condi tions, and that temperature variables may function as major selective force in this case.