摘 要 ：摘要：为提高楸树遗传资源的利用效率，本研究对从楸树基因库中选出的53个无性系进行地径、苗高、节间距等12个性状指标的遗传多样性分析。研究结果表明，53个楸树无性系间地径、苗高的差异极显著，遗传变异系数分别为18.53%、16.29%，遗传多样性指数分别为1.84、1.79。地径、苗高与叶长、叶柄长、叶子总数、叶面积、皮孔密度呈现极显著的正相关，且叶长、叶柄长、叶子总数、叶面积、皮孔密度的遗传变异系数分别为8.57%、17.74%、18.56%、24.21%和26.91%，遗传多样性指数（Shannon-Weaver）分别为1.91、1.87、1.80、1.80和1.94，具较大变异且受强遗传控制，多样性丰富且分布均匀。来源不同的种质资源差别较大，其中来源于河南地区的种质生长指标最优，来源于山东地区的种质变异系数最高。聚类分析将53个无性系分为5大类，第I类的地径、苗高、叶子总数、皮孔密度均值最高，第 II 类生长最差，第III类的节间距、叶长、叶宽、叶柄长、叶面积、叶周长均值最高，第IV类和第V类的叶绿素含量和比叶重均值分别最高。
Abstract:Abstract: In order to improve the utilization efficiency of Catalpa bungei genetic resource, fifty three superior clones from gene bank were selected, and more than twelve trait indices were investigated to analyze their genetic diversity. The result showed that there were very significant differences among clones in seedling height and ground diameter, with their genetic variation coefficients were 18.53%and 16.29%, respectively. And genetic diversity indices were 1.84 and 1.79, respectively. Based on the correlative analysis，there were positive correlation among ground diameter, seedling height and leaf length, petiole length, number of leaves, leaf area and dermal pore density, whose genetic variation coefficients were 8.57%, 17.74%, 18.56%, 24.21, 26.91%, respectively. Genetic diversity index were 1.91, 1.87, 1.80, 1.80, 1.94. So they had relatively large variation and were controlled by highly heredity, which had abundant diversity and distributed uniformly.There were big difference among germplasm from different source, among which the growth indexes of germplasm from Henan area were the best. The growth indexes of germplasm from Shandong area were not the best, but its variation coefficients. Fifty three clones were classified four classes by Cluster analysis, in which the ground diameter, height of seedling, number of leaves and dermal pore density of class I were the highest; the performance of class II was the worst. Internode length, leaf length, leaf width, petiole length, leaf area and leaf perimeter of class III were the biggest. Chlorophyll content,specific leaf weight of class IV and class V were the highest, respectively.