基于曲线拟合的蚕豆病害叶的FTIR研究

摘要

Fourier transform infrared (FTIR) spectroscopy was used to study diseased leaves in broad bean. Results showed that the infrared spectra of different broad bean diseased leaves were similar, which were mainly made up of the vibrational absorption bands of protein,lipid and polysaccharide.There were minor differences in-cluding the spectral peak position, peak shape and the absorption intensity in the range of 1 800-1 300 cm-1. There were obvious differences among their second derivative spectra in the range of 1 800-1 300 cm-1. After the procedure of the Fourier self-deconvolution and curve fitting of health bean leaves and broad bean diseased leaves in the range of 1 700-1 500 cm-1, three sub-peaks were obtained at 1 550 cm-1 (protein amide Ⅱ band), 1 605 cm-1 (lignin) and 1 650 cm-1 (protein amide I band).The ratios of relative areas of the bands of amide Ⅱ, lignin, and amide I were 38.86%, 28.68% and 32.47% in the spectra of healthy leaves, respec-tively. It was distinguished from the diseased leaves (chocolate spot leaf: 15.42%, 42.98% and 41.61%, ring spot leaf:32.39%, 35.63% and 31.98%, rust leaf: 13.97%, 46.40% and 39.65%, yel owing leaf curl disease leaf: 24.01%,36.55% and 39.44%). For sub-peak area ratios (A1 563/A1 605, A1 650/A1 605 and A1 563/A1 654), those of four kinds of diseased leaves were smal er than that of healthy leaves, and there were also differences among four kinds of diseased leaves. The results proved that FTIR combining with curve fitting might be a potential y useful tool for detecting different kinds of broad bean diseases.%用傅里叶变换红外光谱法研究蚕豆病害叶片，结果显示不同病害蚕豆叶片红外光谱图整体相似，它们的红外光谱主要由蛋白质、脂类和多糖的振动吸收带组成，仅在1800～1300 cm－1范围光谱的峰位、峰形及吸收强度有一些微小差异。对1800～1300 cm－1波数范围的光谱图进行二阶导数处理，结果显示蚕豆病害叶的二阶导数谱差异明显。对健康和病害蚕豆叶1700～1500 cm－1范围光谱进行傅里叶自去卷积和曲线拟合处理后，得到蛋白质酰胺Ⅱ带（1550 cm－1）、木质素（1605 cm－1）和酰胺I（1650 cm－1）3个子峰，相应子峰的峰面积比例显示差异，黄化卷叶病分别为24．01％、36．55％、39．44％，赤斑病分别为15．42％、42．98％、41．61％，轮纹病分别为32．39％、35．63％、31．98％，锈病分别为13．97％、46．40％、39．65％，健康叶片分别为38．86％、28．68％、32．47％，健康叶的酰胺Ⅱ带子峰相对面积比病害叶的大，而其木质素子峰相对面积比病害叶的小。对于子峰面积比 A1563／A1605、A1650／A1605和 A1563／A1654，4种病害叶的比值均比健康叶的相应数值小，4种病害叶之间也有差异。结果表明傅里叶变换红外光谱（FTIR）结合曲线拟合可望对不同病害的样品进行有效鉴别。