温度和露时对荔枝霜疫霉侵染发病的影响  

Effects of temperature and wetness duration on litchi downy blight caused by Peronophythora litchii

作　　者：张荣[1] 徐丹丹 姜焰鸣 江立群 习平根 陈厚彬[1] 姜子德 ZHANG Rong;XU Dandan;JIANG Yanming;JIANG Liqun;XI Pinggen;CHEN Houbin;JIANG Zide(College of Horticulture,South China Agricultural University,Guangzhou 510642,China;Department of Applied Chemistry and Biotechnology/Postdoctoral Innovation Practice Base,Shenzhen Polytechnic College,Shenzhen 518055,China;Engineering Fundamental Teaching and Training Center,South China Agricultural University,Guangzhou 510640,China;College of Agriculture,South China Agricultural University/Guangdong Province Key Laboratory of Microbial Signals&Disease Control,Guangzhou 510642,China)

机构地区：[1]华南农业大学园艺学院,广东广州510642 [2]深圳职业技术学院应用化学与生物技术学院/博士后创新实践基地,广东深圳518055 [3]华南农业大学工程基础教学与训练中心,广东广州510642 [4]华南农业大学农学院/广东省微生物信号与作物病害防控重点实验室,广东广州510642

出　　处：《华南农业大学学报》2020年第2期88-94,共7页Journal of South China Agricultural University

基　　金：国家荔枝龙眼产业技术体系建设项目(CARS-3 2);农业农村部热作病虫害疫情监测与防治项目(151821301082351701)

摘　　要：【目的】研究不同温度和露时条件下荔枝霜疫霉Peronophythora litchi病菌孢子囊的萌发和侵染动态,并以此为变量构建数学模型,以期为病害精准预测预报及防控提供参考和依据。【方法】在人工控温、控湿条件下,研究温度(15~30℃)和露时(2~24 h)对荔枝霜疫霉孢子囊萌发和侵染的影响;选用韦布尔模型的修正式,在SAS软件中拟合得到准确度较好的孢子囊萌发和发病严重度模型,进而绘制其对应的等高线风险预测图。【结果】温度、露时及其交互作用可显著影响荔枝霜疫霉孢子囊的萌发及寄主发病的严重度。荔枝霜疫霉孢子囊萌发率和寄主发病严重度随着露时的延长而逐渐升高。在温度为25℃时,所有露时处理条件下的孢子囊萌发率达到最高;露时相同的条件下,当温度为25℃时,孢子囊侵染荔枝果实发病严重度最强。当温度为22~30℃、露时为3~24 h时,叶片的病害严重度超过0.2;孢子囊侵染果实发病迅速且严重,当温度为15~30℃、露时约2~3 h时,果实发病的严重度高于0.6。荔枝霜疫霉侵染叶片和果实发病严重度模型分别为f(t,θ)={1−exp[−(0.1943×t)2]}/cosh[(θ−27.7696)×0.9277/2]和f(t,θ)={1−exp[−(0.4693×t)2]}/cosh[(θ−24.556)×0.1709/2]。【结论】荔枝霜疫病发生依赖于温度和露时,本研究建立的模型可以用于指导生产上防治该病害的施药时间和次数。【Objective】To study the germination and infecting dynamics of sporangia of Peronophythora litchi under different temperature(θ)and wetness duration(t),construct mathematical models based onθand t,and provide references for precision prediction,prevention and control of litchi downy blight.【Method】Under controlled temperature and wetness,the effects of temperature(15 to 30℃)and wetness duration(3 to 24 h)on sporangia germination of P. litchii and its infection on litchi were studied. Using the modified Weibull model, thesporangia germination model and disease severity model with good accuracies were fitted in SAS software. Thecorresponding contour risk prediction maps were drawn.【Result】Sporangia germination and disease severitywere significantly affected by temperature, wetness duration and their interactions. The sporangia germination rateand disease severity increased along with the prolongation of wetness duration. At the temperature of 25 ℃, thesporangia germination rate reached the highest for all wetness duration treatments. In the same wetness duration,the disease severity of litchi fruit was the highest at 25 ℃. When the temperature was 15−30 ℃ and the wetnessduration was 2−3 h, the disease severity of litchi leaf was above 0.2. The sporangia infected fruits seriously andquickly, and the disease severity of fruit was above 0.6 under the temperature of 22−30 ℃ and the wetness durationof 3−24 h. The disease severity models of leaf and fruit due to infection by P. litchii were f(t, θ)={1−exp[−(0.194 3×t)2 ]}/cosh[(θ−27.769 6)×0.927 7/2] and f(t, θ)={1−exp[−(0.469 3×t)2 ]}/cosh[(θ−24.556)×0.170 9/2],respectively.【Conclusion】The occurrence of litchi downy blight depends on temperature and wetness duration.Our models can be used to guide the time and frequency of fungicide application for disease prevention andcontrol.

关 键 词：温度 露时 荔枝霜疫霉 孢子囊 萌发 侵染 模型 

分 类 号：S431[农业科学—农业昆虫与害虫防治]