Huang H, Dane F, Kubisiak T
Am J Bot. 1998 Jul;85(7):1013.
Genetic variation among 12 populations of the American chestnut (Castanea dentata) was investigated. Population genetic parameters estimated from allozyme variation suggest that C. dentata at both the population and species level has narrow genetic diversity as compared to other species in the genus. Average expected heterozygosity was relatively low for the population collected in the Black Rock Mountain State Park, Georgia (He = 0.096 +/- 0.035), and high for the population in east central Alabama (He = 0.196 +/- 0.048). Partitioning of the genetic diversity based on 18 isozyme loci showed that ~10% of the allozyme diversity resided among populations. Cluster analysis using unweighted pair-group method using arithmetric averages of Rogers' genetic distance and principal components analysis based on allele frequencies of both isozyme and RAPD loci revealed four groups: the southernmost population, south-central Appalachian populations, north-central Appalachian populations, and northern Appalachian populations. Based on results presented in this study, a conservation strategy and several recommendations related to the backcross breeding aimed at restoring C. dentata are discussed.
对12个美国栗（Castanea dentata）种群的遗传变异进行了研究。根据等位酶变异估计的种群遗传参数表明，与该属中的其他物种相比，美国栗在种群和物种水平上的遗传多样性都很窄。对于在佐治亚州黑岩山州立公园采集的种群，平均期望杂合度相对较低（He = 0.096 +/- 0.035），而对于阿拉巴马州中东部的种群则较高（He = 0.196 +/- 0.048）。基于18个同工酶位点的遗传多样性划分表明，约10%的等位酶多样性存在于种群之间。使用罗杰斯遗传距离的算术平均值的非加权配对组法进行聚类分析，以及基于同工酶和RAPD位点的等位基因频率进行主成分分析，结果显示有四个组：最南端的种群、阿巴拉契亚中南部种群、阿巴拉契亚中北部种群和阿巴拉契亚北部种群。基于本研究的结果，讨论了旨在恢复美国栗的回交育种的保护策略和若干建议。
