濒危物种巴东木莲的等位酶遗传多样性及其保护策略

为了确定中国特有濒危植物巴东木莲(Manglietia patungensis)的就地保护优先单元和制定迁地保护的取样策略，采用超薄平板聚丙烯酰胺等电聚焦电泳技术对巴东木莲的7个野生居群的等位酶遗传多样性及遗传结构进行了分析。通过对8个酶系统19个酶位点的分析结果来看，巴东木莲具有较高的遗传多样性和一定程度的遗传分化。每位点平均等位基因数（A）为1.57，多态位点百分率（P）为48.1%，平均预期杂合度（H_e）为0.192。巴东木莲居群间的遗传分化系数（G_ST）为0.165，说明其16.5％的遗传变异存在于居群间；基于遗传分化系数计算的基因流（N_m）为1.27，说明居群间存在适度的基因流；固定指数(F)为-0.191，显示巴东木莲居群杂合体轻微过量，纯合体略显不足。本研究表明，目前巴东木莲仍具有较高的遗传多样性并且在其适宜生境中可以完成自然更新，因此应采取以就地保护为主的综合保育策略。

Allozymic genetic diversity in Manglietia patungensis, an endangered species, and its conservation strategies

The allozymic genetic diversity in Manglietia patungensis, an endangered and endemic species of China, was examined by employing isoelectric focusing in thin-layer polyacrylamide slab gels. Nineteen loci of eight enzyme systems were detected and used to estimate genetic diversity within and among populations. The results revealed that high levels of genetic diversity existed in M. patungensis. The average number of alleles per locus(A) was 1.57, the percentage of polymorphic loci (P) was 48.1%, and the mean expected heterozygosity (H e) was 0.192. At the species level, the values of A s, P s, and H es were 1.89, 68.4, and 0.209, respectively. The G ST was 0.165, suggesting that 83.5% of the total genetic diversity was distributed within populations. Average gene flow (N m = 1.27) was moderate. The fixation index (F = -0.191) indicated a slight excess of heterozygotes within populations. Considering the relatively high levels of genetic diversity in M. patungensis populations and the many seedlings regenerating in the largest population, we recommend in situ conservation to maintain viable M. patungensis populations in their original habitats.