基于数量分类法研究中国沉香属物种的形态鉴定特征

Analyzing the Morphological Identification Characteristics of Aquilaria Species in China using Numerical Classification

国内沉香属物种目前仅有白木香(Aquilaria sinensis)和云南沉香(A.yunnanensis)的分布记载,但是关于这两个物种之间的形态鉴定至今仍不清晰。为了准确理解白木香和云南沉香的主要鉴定特征,本研究收集两种沉香属物种共75份植物样品,在此基础对其13个性状进行数量分类学研究,分析性状的变异系数和多样性指数,根据R型、Q型聚类分析法分别对性状和沉香属植物样品进行分类,并通过主成分分析筛选出主要鉴定性状。结果表明:测量性状的变异系数范围为0.09~0.22,质量性状多样性指数为0.59~1.08;R型聚类分析表明,仅腹缝线宽窄程度、种子是否被毛、种子被毛颜色和萼裂片形状4个性状存在相关性,其余性状相对独立;Q型聚类结果显示,类平均法和离差平方和法可将75份沉香属样品准确地划分为白木香和云南沉香2类。主成分分析结果表明,萼裂片形状、种子附属物长度、种子被毛情况、种子被毛颜色和腹缝线宽窄程度是影响两种物种鉴定的主要形态特征。本研究可为沉香属其他物种的数量分类学研究以及种质的选育提供参考依据。

At present,there are only two Aquilaria species in China named A.sinensis and A.yunnanensis.However,the morphological identification between the two species is still unclear.In order to accurately understand the identification characteristics of A.sinensis and A.yunnanensis,13 traits of 75 samples from Aquilaria species were quantitatively classified.We analyzed the variation coefficient and diversity index of the traits,the characters of Aquilaria species samples were classified according to R-type and Q-type cluster analysis,and screened out the main traits by principal component analysis.The results showed that the variation coefficient of measured traits was 0.09~0.22,and the diversity index of quality traits was 0.59~1.08.R-type cluster analysis showed that only the ventral suture,pilose condition of seed surface,color of seed surface pubescence and the shape of calyx lobes were correlated,while the other traits were relatively independent.Q-type cluster analysis showed that 75 samples of Aquilaria species could be accurately divided into two groups by average method and ward.D method:A.sinensis and A.yunnanensis.Finally,the results of principal component analysis showed that calyx lobe shape,length of seed appendage,pilose condition of seed surface,color of seed surface pubescence and ventral suture were the main morphological characteristics affecting the identification of the two species.This study can provide a reference for the quantitative taxonomy and the breeding of germplasm resources of other Aquilaria species.