Survey On Tobacco Infectious Diseases And Field Control Efficiency On Virus Diseases In Linyi, Shandong Province

Tobacco is an economic crop planted as a main source of income for farmers in many tobaccogrowing areas, and is also an important source of national and local tax. Various diseases seriouslyimpact the economic benefit of tobacco and farmers’ income, also bring losses to tobacco enterprises,country and consumers. In this paper, we had a survey on tobacco infectious diseases in Linyi tobaccogrowing area of Shandong Province, and studied the control technology on tobacco virus diseases,mainly focusing on its variety survey and identification, meanwhile also compared the controlefficiency of antiviral biological agents. The main results are the followings.1） In our survey on tobacco infectious disease variety in Linyi, we collected18varieties ofinfectious disease, including6fungus diseases,4bacterial diseases, and8virus diseases. The virusdisease occurred more severely in most regions, while black shank disease and bacterial wilt diseaseoccurred severely in some regions. For the first time Sclerotium rolfsii is reported in Shandong, whilethe bacterial wilt disease expanded its occurrence, and caused severe damage in some regions. Theabove changes were probably caused by adjustment of planting structure and variety replacement.2）The results of survey and identification on tobacco virus diseases in Linyi showed that the mainvirus diseases in this region were PVY, CMV, TMV, TEV, PVX, TRSV, etc., among which PVY, CMVand TMV were the most important, while the largest proportion and widest occurrence appeared in PVY,which mostly occurred in mixture. The most serious disease conversed from TMV to PVY, featuringcompound infection at high extent of damage. Results of field survey showed that the major cultivarsincluding NC89, K326, NC102, were all infected by virus diseases, but the occurrence degree wasapparently different, for example, NC89was more resistant to PVY.3）The application of fast detection technology on tobacco mosaic virus disease has defined thecorrelation between virus-carrying rate of seedlings in greenhouse and occurrence rate in tobacco fields.The virus-carrying rate of0.5%in greenhouse was determined as a threshold value of occurrence infield. Consequently, the virus-carrying rate of seedbed in greenhouse should be controlled below0.5%to prevent the burst of TMV in tobacco fields. The test strip prepared by gold immunochromatographicassay(GICA) proved accurate, sensitive and rapid in the detection of TMV in greenhouse seedlings,which also proved practical and of real-time, and was valuable in rapid diagnose and control of infectedplants in tobacco fields.4）The comparison results of prevention and control efficiency of antivirus biological agent showedthat in various treatments the agronomic traits of tobacco were definitely different, among whichprodigiosin (PG) solution exhibited the best control effect, followed by Serratia marcescensfermentation liquor.