Zhang Zhi-xiang, Liu Peng, Kang Hua-jing, Liao Cheng-chuan, Chen Zi-lin, Xu Geng-di
Laboratory of Biological Science, Zhejiang Normal University, Jinhua 321004, China.
Guang Pu Xue Yu Guang Pu Fen Xi. 2008 Sep;28(9):2081-6.
Emmenopterys henryi, an endemic species in China, has been one of the grade II national key conservation rare and endangered plants. The spectra of stem and leaf of Emmenopterys henryi sampling from seven different geographical populations were determined by Fourier transform infrared (FTIR) spectrometry with OMNI-sampler directly, fast and accurately. A positioning technology of OMNIC E.S.P.5.1 intelligent software and ATR correction was used. It was scanned for the background before the determination of every example. The peak value and absorbance were ascertained using a method of baseline correction in infrared spectra. Based on the indices of wave number-absorbance from 721 to 3366 cm(-1), the differences of these infrared spectra were compared by the methods of principal component analysis (PCA) and cluster analysis. Results showed that there were some differences in FTIR spectra between stem and leaf of Emmenopterys henryi, so it was better to study the diversity of different geographical populations through using the leaf, for which the distance coefficient of clustering analysis plot and the position relationship of principal component analysis three-dimensional plot of the seven populations were bigger. Being far away from others populations, the infrared spectra of Emmenopterys henryi in Dapan Mountain and Gutian mountain had special characteristics, indicating significant diversity. At the same time, the infrared spectra of Jiulong Mountain, Wuyan Mountain and Songyang populations had their own characteristics. There were no significant difference in the position relationship of three-dimensional plot and distance coefficient of clustering analysis plot, showing that the chemical compositions of these three populations were of little difference, and the diversity differentiation was not remarkable. However, there were some significant differences in populations' diversity between Fengyang Mountain and Wencheng. It was indicated that the chemical composition of Emmenopterys henryi was affected by the special geographic positions and environment conditions. In a word, the remarkable differences in the chemical compositions of Emmenopterys henryi populations were consistent with their geographic distance far and near. The results also showed that there was good correspondence between the position relationship of PCA three-dimensional plot and distance coefficient of clustering analysis plot of the samples based on the indices of wave number-absorbance of FTIR and their geographic distance relationship. Therefore, FTIR can be used widely for studying and protecting the rare and endangered plants. It is not only provides the theoretic base of community ecology and ecosystem ecology of Emmenopterys henryi, but also has important theory and realistic meaning for exploring the mechanism of species endangerment, protecting and proliferating the populations of Emmenopterys henryi.
香果树是中国特有的物种，一直是国家二级重点保护的珍稀濒危植物之一。采用傅里叶变换红外光谱仪（FTIR）和OMNI采样器，直接、快速、准确地测定了来自七个不同地理种群的香果树茎和叶的光谱。使用OMNIC E.S.P.5.1智能软件的定位技术和衰减全反射（ATR）校正。在测定每个样品之前先扫描背景。采用红外光谱基线校正方法确定峰值和吸光度。基于721至3366 cm(-1)波数-吸光度指标，通过主成分分析（PCA）和聚类分析方法比较这些红外光谱的差异。结果表明，香果树茎和叶的FTIR光谱存在一些差异，因此通过叶片研究不同地理种群的多样性更好，七个种群聚类分析图的距离系数和主成分分析三维图的位置关系在叶片上更大。大盘山和古田山的香果树红外光谱远离其他种群，具有特殊特征，表明多样性显著。同时，九龙山、乌岩山和松阳种群的红外光谱有各自特点。三维图位置关系和聚类分析图距离系数无显著差异，表明这三个种群的化学成分差异不大，多样性分化不明显。然而，凤阳山和文成种群的多样性存在一些显著差异。表明香果树的化学成分受特殊地理位置和环境条件影响。总之，香果树种群化学成分的显著差异与其地理距离远近一致。结果还表明，基于FTIR波数-吸光度指标的样品主成分分析三维图位置关系和聚类分析图距离系数与其地理距离关系具有良好的对应性。因此，FTIR可广泛用于珍稀濒危植物的研究和保护。它不仅为香果树群落生态学和生态系统生态学提供理论基础，而且对探索物种濒危机制、保护和增殖香果树种群具有重要的理论和现实意义。
