基于傅里叶变换红外光谱的葡萄褐斑病研究

摘要

利用傅里叶变换红外（Fourier Transform Infrared，FTIR）光谱研究了葡萄褐斑病病叶和正常叶片。测试分析了大褐斑病叶病斑处和非病斑处、小褐斑病叶病斑处和非病斑处、未染病正常叶片的红外光谱，结果显示：葡萄叶片光谱主要由碳水化合物、蛋白质、脂类的吸收带组成。褐斑病叶片光谱与正常叶片红外光谱变化主要在1800-1500 cm-1范围脂类、蛋白质酰胺的吸收区和1200-900 cm-1范围多糖的吸收区。用1800-1500 cm-1范围拟合峰的峰面积比 A1657／A1517考察蛋白质相对含量变化，A1738／A11517考察脂类相对含量变化，用吸光度比 I1066／I1441考察多糖相对含量变化，结果显示患褐斑病的葡萄叶中脂类、蛋白质、糖类等营养物质含量降低。褐斑病和正常葡萄叶红外光谱的二阶导数光谱结合聚类分析方法，利用1800-1500 cm-1与1200-900 cm-1范围数据进行聚类分析，结果将正常叶片与患褐斑病叶片准确区分开。证明褐斑病叶片红外光谱在1800-1500 cm-1与1200-900 cm-1范围为敏感谱带。%Fourier transform infrared (FTIR)spectroscopy was used to study healthy and diseased leaves of grape.The infrared spectra of non-lesion site and lesion site of grape large brown spot leaves,non-lesion site and lesion site of grape small brown spot leaves were tested and analyzed,and so did healthy grape leaves.The results show that the infrared spectra of grape leaves are mainly composed of the absorption bands of carbohydrates,proteins and lipids.The infrared spectra of healthy and diseased leaves of grape exhibit differences in the region of 1 800-1 500 cm-1 for lipid and protein amide absorption,and in the range from 1 200 to 900 cm-1 for polysaccharide absorption.Decomposition and curve-fit-ting analysis was performed on the infrared spectra of healthy and diseased leaves in the region of 1 800-1 500 cm-1 .The sub-band area ratio A1657 /A1517 was used to evaluate the relative changes of proteins in the leaves,and A1738 /A1517 was used to evaluate the relative changes of lipids in the leaves.The absorption ratio I1066 /I1441 was used to evaluate the rela-tive changes of polysaccharides in the leaves.The results indicated that the content of polysaccharides,proteins and lip-ids in grape brown spot leaves had decreased.Hierarchical cluster analysis (HCA)was performed on the second deriva-tive infrared spectra of healthy and diseased leaves of grape in the range from 1 800 to 1 500 cm-1 and 1 200 to 900 cm-1 ;and can correctly cluster the grape leaf samples for healthy or diseased.All above have revealed that infrared spec-tra of grape brown spot leaves in the regions of 1 800-1 500 cm-1 and 1 200-900 cm-1 are sensitive bands.