Classification Of Magnoliaceae And Bamboo Species Based On Fourier Transform Infrared Spectroscopy

In this dissertation, Fourier transform infrared (FTIR) spectroscopy combinedwith statistical analysis was used to study the magnoliaceae and bamboo leaves. Theresults showed that the infrared spectra of magnoliaceae and bamboo leaves weremainly composed of the bands of polysaccharides, protein and lipids. The infraredspectra of leaves belonging to three magnoliaceae subtribe were similar. Fouriertransform infrared spectroscopy combined with principal component analysis (PCA)and hierarchical cluster analysis (HCA) were utilized to study the magnoliaceaesubtribes cluster. HCA and PCA were performed on the second derivative infraredspectra in the range1800-700cm-1, the results showed that all samples were dividedinto three groups.The influence of leaf senescence on magnoliaceae cluster was studied by FTIRspectroscopy. FTIR spectra of young, mature and old yellow leaves were obtainedfrom14species trees belonging to the three magnoliaceae subtribes. Decompositionand curve-fitting analysis was performed in the region of1800-1480cm-1. Thesub-band absorption ratios of H1655/H1735, A1604/A1735, A1055/A2922were used toevaluate the relative changes of protein, lignin and polysaccharides in the leaves. Theresults show that the accumulation and mobilization of protein, lignin andpolysaccharides during leaf growing period were different. Hierarchical clusteranalysis and principal component analysis were performed on the second derivativeinfrared spectra in the range1800-700cm-1. It is proved that principal componentanalysis and hierarchical cluster analysis were influenced by leaf senescence onmagnoliaceae cluster. The cluster based on mature leaves are better than young andold yellow leaves. Our study suggests that it should be cautious to select leaf samplewhile using leaf spectra for classification.Fourier transform infrared spectroscopy was used to study bamboo leaves. FTIRspectra of54leaves from6species of bamboo were obtained. The results showed thatthe infrared spectra of bamboo leaves were similar. PCA and HCA were performed onthe second derivative infrared spectra in the range1800-700cm-1. The PCA and HCA results showed that all bamboo samples were correctly classified into six groups. It isproved that FTIR spectroscopy combined with statistical analysis could be used todiscriminate bamboo at species level.It is proved that FTIR spectroscopy combined with statistical analysis could beused to study the plant clusters.