利用AFLP分子标记对滇西北玉龙雪山不同海拔(2 750~3 500 m)川滇高山栎(Quercus aquifolioides)6个居群进行遗传多样性分析。结果表明:川滇高山栎多态位点比率为100%,Shannon多样性指数I为0.54,Nei's基因多样性指数H_e为0.37,反映出川滇高山栎总的遗传多样性丰富,处于较高水平;由Shannon信息指数计算的值比Nei指数估算的居群遗传多样性高,但两者都一致表明6个居群的遗传多样性水平随海拔梯度的变化而呈现相同的变化规律:海拔3 050~3 350 m川滇高山栎的遗传多样性水平较高,而海拔2 750~2 900 m及3 500 m居群的遗传多样性水平均有降低的趋势。本研究中川滇高山栎的遗传分化系数G_(st)为0.089,表明居群间的遗传变异占总的遗传变异的8.90%,而91.10%的遗传变异存在于居群内,AMOVA分析表明11.00%的变异存在于居群间,89.00%的变异存在于居群内,两者都说明川滇高山栎居群间存在较低的遗传分化,总的遗传分化主要来自居群内部。基因流N_m为5.12,表明较高的基因流可能是导致川滇高山栎具有较高的遗传多样性的主要原因之一。

The genetic diversity of Quercus aquifolioides population located at different altitudes (2 750- 3 500 m) of Jade Dragon Snow Mountain in the northwest of Yunnan Province was investigated with amplification fragment length polymorphisms (AFLPs) markers.The results showed that the ratio of polymorphic loci was 100%.Shannon diversity index I was 0.54 and the Nei's gene diversity index H_e was 0.37,indicating that the Quercus aquifolioides had high genetic diversity at species level.I and H_e were agreed,indicating that the genetic diversity of 6 populations varied with altitude gradient.The genetic diversity from 3 050 m to 3 350 m was high.The genetic diversity of 2 750-2 900 m and 3 500 m group was decreased.Results of the genetic differentiation of Quercus aquifolioides G_(st) (0.089) and AMOVA analysis (Phist = 0.110) showed that there was a low level of genetic differentiation among populations.Gene flow among population was 5.12,suggesting that high gene flow may be a main factor leading to high levels of the genetic diversity among populations.