液滴飞溅对土壤中黄瓜棒孢叶斑病菌传播的影响

Effect of droplet splash on the dispersal of soil-borne Corynespora cassicola cusing cucumber leaf spo

由多主棒孢菌(Corynespora cassiicola)侵染引起的黄瓜棒孢叶斑病是黄瓜生产中的重要病害,土壤带菌是其重要的初侵染源。为了明确液滴飞溅对土壤中病菌传播的影响,本研究建立了土壤中C.cassiicola的qPCR快速检测体系。利用该检测体系从黄瓜棒孢叶斑病自然发病棚室的土壤样本中检测到C.cassiicola带菌量为27.00×10^(0)-7.95×10^(5)pgDNA·g^(-1)。液滴撞击能引起土壤或基质中的C.cassiicola飞溅,使空气中的病原菌浓度达到2.71×10^(3)~3.36×10^(3)pgDNA·m^(-3),造成黄瓜发病(土壤和基质带菌的病情指数分别为65.56和41.56)。在带菌土壤或基质表面覆膜可使空气中C.cassiicola浓度降至10.24~12.11pgDNA·m^(-3),显著减轻了病害的发生(带菌土壤和基质覆膜后的病情指数分别为13.79和13.83)。本研究明确了液滴撞击飞溅是土壤中C.cassiicola传播的重要方式,为黄瓜棒孢叶斑病的监测预警提供了技术手段,为病害防控提供了理论依据。

Cucumber leaf spot caused by Corynespora cassicola is an important disease in cucumber production,and diseased residues in soil have been proved to be the main source of its initial infection.To clarify the effect of droplet splash on the dispersal of the pathogen,a real-time fluorescence quantitative PCR(qPCR)-based system for rapid detection of C.cassicola in soil was established.Through this system,C.cassicola was detected in soil samples collected from greenhouses where Corynespora leaf spot was naturally occurred,with concentrations ranging from 27.00×10^(0) to 7.95×10^(5)pgDNA·g^(-1).The results of artificial simulation of droplet splashing experiment showed that the impact of droplets carrying C.cassicola led to splash dispersal of the pathogen and increased disease severity,with disease index of 65.56 and 41.56 for C.cassicola-infected soil and substrate,respectively.Mulching soil and substrate surface in the above experiment significantly reduced disease severity,with disease index of 13.79 and 13.83 for C.cassicola-infected soil and substrate,respectively.The results of this study indicate that droplet splash is an important route for the transmission of soil-borne C.cassicola,providing not only technical assistance for monitoring and early warning of Corynespora leaf spot but also theoretical basis for the prevention and control of the disease.