Department of Plant Biology, 2502 Plant Sciences Building, University of Georgia, Athens, Georgia 30602 USA;
Am J Bot. 2004 Apr;91(4):540-8. doi: 10.3732/ajb.91.4.540.
Genetic diversity was examined at 16 allozyme loci in 21 wild populations of the medicinal plant American ginseng, Panax quinquefolius L. (Araliaceae). This species has been harvested from forests in North America for more than 250 years. Average expected heterozygosity was significantly greater within protected populations (H(e) = 0.076) than within populations in which harvesting was permitted (H(e) = 0.070). More notably, genetic structure was greater among unprotected populations (G(ST) = 0.491) than among protected populations (G(ST) = 0.167). These differences in the level and distribution of genetic diversity in American ginseng populations indicate that harvesting may have significant evolutionary implications for this species. Age class structure also shifted toward smaller, nonreproductive plants in unprotected populations. Juvenile plants had lower genetic diversity (H(e) = 0.067) than reproductive plants (H(e) = 0.076) suggesting that conserving a proportion of the largest (oldest) plants in each population is important to protect reproductive fitness and the evolutionary potential of the species. Due to its high genetic structure, conservation recommendations include protecting populations throughout the range of P. quinquefolius.
遗传多样性在 16 个等位酶基因座中进行了检查，涉及 21 个野生美洲人参（五加科）种群。这种植物已经从北美的森林中收获了超过 250 年。在受保护的种群中，平均预期杂合度显著高于允许收获的种群（He = 0.076）。更值得注意的是，未受保护的种群之间的遗传结构更大（G（ST）= 0.491），而受保护的种群之间的遗传结构更小（G（ST）= 0.167）。这些美洲人参种群中遗传多样性水平和分布的差异表明，收获可能对该物种具有重要的进化意义。未受保护的种群中年龄类结构也向较小的、非繁殖植物转移。幼龄植物的遗传多样性较低（He = 0.067），低于繁殖植物（He = 0.076），这表明保护每个种群中最大（最老）植物的一部分对于保护繁殖适应性和物种的进化潜力非常重要。由于其高度的遗传结构，保护建议包括保护 P. quinquefolius 分布范围内的种群。
