叶片衰老影响木兰科植物聚类的FTIR研究

FTIR Study of the Influence of Leaf Senescence on Magnoliaceae Cluster Analysis

傅里叶变换红外光谱(FTIR)结合聚类分析技术应用于木兰科植物不同亚族分类,研究了叶片衰老对聚类分析效果的影响。测试了木兰科三个亚族14种植物的幼叶、成叶、老黄叶红外光谱,结果显示三个亚族植物叶片红外光谱差异不大;同种植物叶片不同生长期的红外光谱吸收峰位置基本一致,但一些特征峰的峰强有变化;用1 800～700cm-1范围二阶导数光谱结合聚类分析,发现成叶二阶导数光谱聚类分析能够正确对样品分类,幼叶和老黄叶二阶导数谱聚类分析效果不如成叶,说明叶片衰老过程化学成分变化影响聚类分析效果,聚类分析时取成叶样品为好。

Fourier transform infrared（FTIR）spectroscopy combined with hierarchical cluster analysis was used to study the influence of leaf senescence on magnoliaceae cluster.FTIR spectra of young,mature and old yellow leaves were obtained from 14 species trees belonging to the three magnoliaceae subtribes.Results showed that the infrared spectra of the three subtribes plant leaves were similar,only with minor differences in the absorption intensity of several peaks.Hierarchical cluster analysis was performed on the second derivative infrared spectra in the range 1 800～700cm^-1.The HCA results showed that the cluster based on mature leaves is better than that based on young and old yellow leaves.Our study suggests that it should be cautious to select leaf sample while using leaf spectra for classification.