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。

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.