中文摘要：

以东北和华北地区5个种源的小叶杨为材料,分别对17个表型及生理性状进行了比较分析。结果表明：小叶杨各性状在种源间和种源内均存在广泛的遗传变异;平均表型分化系数（VST）为47.11%,种源内变异大于种源间变异;小叶杨群体各性状变异呈梯度变化规律,高海拔的种源表现为苗高、叶大,而低海拔的种源表现则相反;利用种源间欧氏距离进行UPGMA聚类,结果显示,5个小叶杨种源可以划分为3类。研究结果将为天然小叶杨遗传资源的保存和利用提供理论依据。

英文摘要：

Seventeen morphological and physiological traits of Populus simonii were analyzed among and within five provenances distributed in northeastern and the North China.Analysis of variance for all traits showed that there were significant differences among provenances and individuals within provenances.The mean phenotypic differentiation coefficient（VST） for all traits was 47.11%,which meant that the variation within provenances was slightly higher than that among provenances.The analysis of correlation between the morphological and physiological traits of P.simonii and the geographical and climatic factors indicated that the variations among populations presented gradient regularity.In contrast to the lowelevation provenances,individuals from high-altitude provenances displayed high trees and large leaves.According to the UPGMA cluster analysis based on the Euclidean distance,five provenances of P.simonii investigated could be divided into three groups.The results provide theoretical basis for conservation and utilization of natural P.simonii genetic resources.