【目的】通过观测彩叶桂品种的枝叶性状并进行数量分类研究,为彩叶桂品种分类和优良品种选育提供参考依据。【方法】于春季对25个彩叶桂品种进行形态学特征观察,以观测的35个枝叶性状指标数据进行R型聚类分析和主成分分析,去掉相关性较大且累积贡献率较小的性状指标,然后对25个彩叶桂品种进行Q型聚类分析。【结果】R型聚类结果显示:除彩叶桂叶面是否皱缩和侧脉是否隆起,叶片横切面与主脉凹凸度,叶柄颜色与新枝是否双色,成熟叶叶色、成熟叶有无花斑、幼叶色彩类型、叶片色彩类型、幼叶颜色和叶色有较明显的相关性外,各性状相对独立。主成分分析结果显示:共提取11个主成分,累计贡献率为87.618%,前9个主成分累计贡献率为81.157%,主要反映了彩叶桂各阶段色彩表现、叶大小、叶缘锯齿及叶面形态等。Q型聚类结果显示:25个彩叶桂品种按成熟叶叶色分为2大类,又由叶宽分为3类,最后根据叶宽、幼叶色彩类型、叶片横切面、叶形、叶片质地和叶脉色彩等分为10个组。【结论】R型聚类分析、主成分分析和Q型聚类分析表明,叶色、幼叶颜色、成熟叶叶色、叶型、叶面是否皱缩、叶片横切面、叶宽和叶形等性状可作为彩叶桂品种形态学分类的性状指标。综合而言,成熟叶叶色、叶片横切面和叶宽是此次数量分类得出的主要的标准和依据,但是否为该树种最主要的分类标准和依据还需进一步探讨和验证。

【Objective】 Numerical classification was carried out by observing the leaf and branch characteristics of Osmanthus fragrans cultivars. The results will provide a reference for their breeding and classification. 【Methods】 The morphological characteristics of 25 O. fragrans cultivars were observed in spring. Thirty-five leaf and branch characteristics were used for R-type clusters and a principal component analysis (PCA). After removing characteristics with a high correlation and low cumulative contribution, 35 characteristics were selected to conduct the classification of color-leafed O. fragrans colour cultivars with the Q-type cluster analysis. 【Results】 The R-type clusters showed that several variables (whether the leaf surface was wrinkled or not, whether the lateral veins were uplifted or not, petiole color, whether the new branches were dichromatic or not, the convex-concave degrees of the transverse section and the main vein of the leaves, and whether there were spotted blades on the mature leaves or not), were all significantly correlated with the color and color type at each stage of the leaves. All the other factors were relatively independent. The PCA showed that 11 principal components were extracted, their cumulative contribution was 87.618%. The cumulative contribution of the top nine principal components was 81.157%, mainly reflecting leaf colour representation in all stages, leaf size, serrated leaf margin, and leaf shape. The results of the Q-type cluster showed that the 25 O. fragrans cultivars were divided into the following: two categories based on the color of mature leaves; three categories based on average leaf width; and 10 categories according to the leaf width, the young leaf color type, leaf cross section, leaf shape, and leaf texture. 【Conclusion】 In general, the color of mature leaves, the cross section of the blade and the leaf width may be the most important criteria and the basis for the classification of color-leafed O. fragrans cultivars. However, this needs to be explored and verified.