分光光度计法在甘蔗白条病致病菌菌液浓度测定上的应用  

Concentration Determination for Pathogenic Bacteria Suspension of Sugarcane Leaf Scald Disease by Spectrophotometry

作　　者：孔春艳 毛钧[1] 刘新龙[1] 林秀琴[1] 魏春燕[2] 徐超华[1] 李旭娟[1] 刘洪博[1] 李纯佳[1] 陆鑫[1] KONG Chunyan;MAO Jun;LIU Xinlong;LIN Xiuqin;WEI Chunyan;XU Chaohua;LI Xujuan;LIU Hongbo;LI Chunjia;LU Xin(Sugarcane Research Institute,Yunnan Academy of Agricultural Sciences/Yunnan Key Laboratory of Sugarcane Genetic Improvement,Yunnan Kaiyuan 661699;Sugarcane Research Institute,Guangxi Academy of Agricultural Sciences,Guangxi Nanning 530007)

机构地区：[1]云南省农业科学院甘蔗研究所/云南省甘蔗遗传改良重点实验室,云南开远661699 [2]广西农业科学院甘蔗研究所,南宁530007

出　　处：《中国糖料》2022年第4期49-54,共6页Sugar Crops of China

基　　金：国家重点研发计划项目(2019YFD1000500);云南省重大科技专项“生物资源数字化开发应用”(202002AA100007);农业农村部政府购买服务项目(19210151)资助。

摘　　要：采用分光光度计法,建立快速准确测定白条黄单胞杆菌菌液浓度的方法。首先在4个波长下,以分光光度计测定的不同稀释浓度白条黄单胞杆菌菌悬液光密度值(OD值)为自变量x,以平板计数法获得的对应稀释浓度菌悬液细菌浓度为因变量y,分别建立二者间的标准曲线和线性回归方程;根据回归方程的决定系数(R2)最大化、均方根误差(RMSE)和相对均方根误差(NRMSE)最小化原则筛选出最适波长和最优线性回归方程,最终实现菌悬液浓度的快速估算。结果表明,在4个波长下,平板计数法测定的白条黄单胞杆菌菌液浓度(0.5×10^(8)~12.5×10^(8) cfu/mL)与分光光度计测定的OD值(0.03~1.95)之间线性关系良好,其中在600 nm波长下建立的标准曲线线性回归方程y=11.263x+0.117为最优方程,决定系数R^(2)为0.9967,绝对误差RMSE为0.26×10^(8) cfu/mL,相对误差NRMSE为4.93%。通过进一步应用验证,该回归方程预测结果与平板计数结果无显著差异(P>0.05)。研究结果可靠准确,可作为测定白条黄单胞杆菌菌液浓度的标准方法进行应用。In this study one method to measure the pathogenic bacteria suspension of sugarcane leaf scald disease(Xanthomonas albilineans)was established by spectrophotometry.Firstly,under wavelength of 420 nm,450 nm,600 nm,and 660 nm,the optical density value(OD)of different concentration bacteria suspension,as independent variable x,was determined by spectrophotometry,and the concentration of bacteria suspension,as dependent variable y,was obtained by plate counting method.Accordingly,the standard curves and linear regression equations for x and y ware established under different wavelength;then the suitable wavelength and optimal linear regression equation were selected according to the principles of coefficient of determination(R^(2))maximization,and root mean square error(RMSE)and relative root mean square error(NRMSE)minimization;and also,the reliability of the optimal regression equation was verified.The results showed,under 420 nm,450 nm,600 nm,and 660 nm wavelength,the linear relationship between the concentration of bacteria suspension(0.5×10^(8)-12.5×10^(8) cfu/mL)and the OD value(0.03-1.95)determined by spectrophotometry was good,where the linear regression equation y=11.263x+0.117 established under 600 nm wavelength was the optimal equation,with R^(2)=0.9967,RMSE=0.26×10^(8) cfu/mL,NRMSE=4.93%.In further validation experiment,there was no significant difference detected between the prediction value of the optimal regression equation and the plate count values at P>0.05 level.The above study results have proved that the spectrophotometry was convenient,rapid,and the result was also reliable and accurate.So,it could be be recommended as a standard method for rapid concentration determination of pathogenic bacteria suspension of sugarcane leaf scald disease(Xanthomonas albilineans).

关 键 词：甘蔗白条病 白条黄单胞杆菌 分光光度计法 平板计数法 线性相关 

分 类 号：S435.661[农业科学—农业昆虫与害虫防治]