基于傅里叶变换红外光谱的大白菜根肿病定量测评

摘要

Clubroot ,caused by Plasmodiophorabrassicae ,is considered the most devastating soilborne disease in Brassica crops . It has emerged as a serious disease threatening the cruciferous crop production industry in China .Nowadays ,the detection tech-niques for P .brassicae are laborious ,time-consuming and low sensitivity .Rapid and effective detection methods are needed .The objective of this study is to develop a Fourier transform infrared spectrometer (FTIR) technique for detection of P .brassicae ef-fectively and accurately .FTIR and Real-time PCR techniques were applied in quantitative detection of P .brassicae .Chinese cab-bages were inoculated with P .brassicae .By analyzing the FTIR spectra of P .brassicae ,infected clubroots and healthy roots , three specific bands 1 105 ,1 145 and 1 228 cm-1 were selected .According to the correlation between the peak areas at these sen-sitive bands and Real-time PCR Ct value ,quantitative evaluation model of P .brassicae was established based on FTIR y=34.17+12.24x1 -9.81x2 -6.05x3 ,r=0.98 (p<0.05) .To validate accuracy of the model ,10 clubroot samples were selected ran-domly from field ,and detected by FTIR spectrum model ,the results showed that the average error is 1.60% .This demonstra-ted that the FTIR technology is an available one for the quantitative detection of P .brassicae in clubroot ,and it provides a new method for quantitative and quickly detection of Chinese cabbage clubroot .%大白菜根肿病是白菜生长中的“癌症”，近年来在我国大面积发生，造成巨大经济损失。现有技术不能满足生产中对根肿病检测的需求，迫切需要一种快速、简便的大白菜根肿病定量化测评及检测技术。本研究利用傅里叶变换红外光谱（Fourier transform infrared spectrometer ，FTIR）结合荧光定量 PCR（Real-time PCR）技术，进行大白菜根肿病的定量测评技术研究。通过分析芸薹根肿菌、大白菜发病肿根和健康根的FTIR光谱，选择了1105，1145和1228 cm －1三个根肿菌检测的特异性谱带，利用这三个谱带的峰面积值，建立了芸薹根肿菌的FTIR定量测评模型 y＝34.17＋12.24x1－9.81x2－6.05x3，相关系数 r＝0.98（p＜0.05）。为了验证模型的有效性，田间随机选取10株大白菜根肿病样本，根据建立的大白菜根肿病FTIR光谱定量测评模型，计算大白菜根肿菌C t值，结果显示平均预测误差为1.60％。说明试验构建的线性模型测定效果良好，可以根据大白菜根部样本的红外光谱，判断芸薹根肿菌的含量。本研究为十字花科蔬菜根肿病的定量、快速检测提供新的手段，为田间根肿菌的预测预防奠定基础。