小叶锦鸡儿天然居群叶形态性状变异研究

为揭示小叶锦鸡儿(Caragana microphylla)天然居群叶形态性状的变异规律及其生态适应性特征，该研究以10个小叶锦鸡儿天然居群为对象，通过多重比较、巢式方差分析、相关性分析、聚类分析和主成分分析等方法，对7个叶形态性状进行分析。结果表明：(1)小叶锦鸡儿叶形态性状在居群内和居群间均存在极显著差异(P < 0.01)，平均变异系数为10.13%，不同性状的变异幅度为6.23%~12.78%；平均叶形态性状的表型分化系数为43.62%，居群内变异(30.09%)大于居群间变异(24.91%)，说明居群内是其叶形态性状变异的主要来源。(2)相关性分析表明，环境因子对小叶锦鸡儿的叶形态性状变异有很大的影响，在地理空间上主要呈现出沿海拔梯度的变异模式；主成分分析的结果显示，小叶宽、叶柄宽和叶柄长对小叶锦鸡儿叶形态变异起主导作用；利用欧式距离对小叶锦鸡儿居群进行UPGMA聚类分析结果显示，基于叶形态性状和环境因子可分别将小叶锦鸡儿10个居群分为3类和2类，Mantel检验结果表明，小叶锦鸡儿的叶形态性状变异不存在地理连续性。研究结果为小叶锦鸡儿的适应性进化和开发利用提供了理论依据。

Leaf Morphological Trait Variations in Natural Populations of Caragana microphylla

In order to reveal the pattern of variation and ecological adaptation of leaf morphological traits in the natural populations of Caragana microphylla, we collected leaves from ten natural populations of C. microphylla. We analyzed seven leaf morphological traits by multiple comparisons, nested analysis of variance, correlation analysis, cluster analysis and principal component analysis (PCA). The results showed that: (1) extremely significant (P < 0.01) variations of leaf morphological traits of C. microphylla were found within and among populations. The mean coefficient of variation (CV) was 10.13%, ranged from 6.23% to 12.78%. The mean phenotypic differentiation coefficient for all morphological traits was 43.62%, and the variation within population (30.09%) was higher than that among populations (24.91%), indicating that the leaf morphological variation within population was the main source of leaf morphological variation in C. microphylla. (2) Environmental factors also affected the variation of leaf morphological traits of C. microphylla, especially along the altitudinal gradient. The PCA results indicated that leaflet width, petiole width and petiole length played dominant roles. The results of UPGMA clustering analyses showed that ten populations of C. microphylla could be divided into three groups and two groups on the basis of leaf morphological traits and environmental factors, respectively. The Mantel test showed there was no geographic continuity in the variation of leaf morphological traits in C. microphylla. Overall, these results provided critical information for the adaptive evolution and utilization of the important species.