Analysis of Phylogenetic Relationships of Main Citrus Germplasms Based on Ftir Spectra of Petals

To develop a quick, accurate and reliable technique for studying phylogenetic relationship of Citrus, FTIR (Fourier transform infrared spectroscopy) technique was used. The petals spectra of eighteen varieties of citrus germplasms were investigated by FTIR. Pretreatment methods of raw spectra (2000-500cm(-1)) were composed of baseline correction, normalize and first derivative (Savitzky-Golay). We used One-way ANOVA (analysis of variance) and Tukey's HSD (honestly significant difference) to extract effective wave bands, where the spectral absorbance values of different citrus germplasms were significantly different. The results showed that 2000 similar to 1831cm(-1), 1763 similar to 1595cm(-1), 1517 similar to 1090cm(-1), 1035 similar to 1024cm(-1), 950 similar to 935cm(-1), 861 similar to 784cm(-1), 744 similar to 721cm(-1) and 653 similar to 608cm(-1) were the effective wave bands. HCA (hierarchical cluster analysis) was adopted to classify citrus germplasms based on the above eight effective wave bands. It was found that eighteen citrus varieties were classified into six subgroups. The results of classification and citrus phylogenetic relationships between six subgroups were consistent of results from Morphology, Biochemistry, Cytology and Molecular Biology. The overall results demonstrated that fourier transform infrared spectroscopy technique with One-way ANOVA and Tukey's HSD and hierarchical cluster analysis model were promising for the rapid, accurate and reliable classification for citrus as well as studying citrus phylogenetic relationship.