利用FTIR和化学计量学对牛肝菌亲缘关系的研究

摘要

采用傅里叶变换红外光谱结合化学计量学对不同种牛肝菌亲缘关系进行研究,为该种群亲缘关系鉴定提供依据,同时为人工栽培牛肝菌奠定理论基础.采集12个种类72份牛肝菌样品的红外光谱,采用二阶导数(2D)、标准正态(SNV)变量和小波压缩(WC)等方法对牛肝菌的原始红外光谱进行优化处理,结合偏最小二乘判别分析(PLS-DA)建立鉴别模型.将PLS-DA得到的前8个主成分数据作为提取数据代入系统聚类分析(HCA),获得亲缘关系树状图.结果显示:12种牛肝菌的原始红外光谱较为相似,共有峰主要归属为蛋白质、多糖、纤维素和氨基酸等物质中O-H、C=O、C-O-H、C=O、C-C等官能团的吸收峰.对比不同优化处理的鉴别结果,发现2D+WC预处理方法对不同种类牛肝菌区分效果较好.HCA亲缘关系树状图表明,按照物种层面划分,中华牛肝菌和远东疣柄牛肝菌亲缘关系最近,且2种牛肝菌与圆花孢牛肝菌亲缘关系较近;深褐牛肝菌和美味牛肝菌亲缘关系较近;小美牛肝菌和美柄牛肝菌亲缘关系较近,且2种牛肝菌与栗色牛肝菌亲缘关系较近.傅里叶变换红外光谱法可应用于牛肝菌的亲缘关系分析,能为野生食用菌的亲缘关系研究提供一种新方法.%In order to establish a new method for identifying the genetic relationships and provide theoretical basis for artificial cultivation of bolete mushrooms,fourier transform infrared (FTIR) spectroscopy combined with Chemometrics was used to study the genetic relationships among different species of bolete mushrooms samples.A total of 72 infrared spectra of 12 different species of boletes were collected and processed by using second derivative(2D),standard normal variate(SNV) and wavelet compression(WC).Then the processed spectra were used to establish a discrimination model based on partial least squares discriminant analysis(PLS-DA).Hierarchical cluster analysis was performed by the method of between-groups linkage and Euclidean distance according to the eight principal components which were obtained by PLS-DA and the results of HCA were displayed as dendrograms.The results showed that all of the original infrared spectra were similar.The common absorption peaks were mainly assigned to the functional groups of O-H,C =O,C-O-H,C =O and C-C of protein,polysaccharide,fibres and amino acid.Comparing the discrimination results of samples with spectra processed by different methods,better discrimination could be accomplished when the spectra were processed by 2D + WC.From the clustering results of different species,Boletus sinicus and Leccinum extremiorientale had the closest relationship and these two species were close to Heimioporus retisporus.B.obscureumbrinus and B.edulis had a close relationship while the relationship between B.speciosus and B.calopus was also close and both of these two mushrooms were similar to B.umbriniporus.The results suggest that FTIR can be used in the study of genetic relationship of bolete mushrooms,which may provide a new method for studying the genetic relationship of wild edible mushrooms.