基于傅里叶变换红外光谱的大白菜根肿病定量测评

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1 105，1 145和1 228 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Ct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。

Quantitative Detection of Chinese Cabbage Clubroot Based on FTIR Spectroscopy

Clubroot, caused by Plasmodiophora brassicae, 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 techniques 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 effectively and accurately. FTIR and Real-time PCR techniques were applied in quantitative detection of P. brassicae. Chinese cabbages 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 sensitive 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 randomly from field, and detected by FTIR spectrum model, the results showed that the average error is 1.60%. This demonstrated 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.