Studies And Uses Of New-type Biological Fungicide(Fungi Polysaccharide) On Tobacco Disease Control

Tobacco is an important cash crops, it has a very important role in agricultural production.However, the occurrence of disease on tobacco brings huge economic losses to China everyyear. Tobacco cucumber mosaic virus (CMV) is one of the main diseases on tobacco, it hasbrought huge economic losses to tobacco production in China. At this stage, there are manypreventions and treatments on tobacco CMV, such as planting resistant varieties, agriculturalcontrol and chemical control. Chemical control is the most simple, fast and effective way ofprevention. However, with the emergence of chemical pesticide residues, environmentalpollution and so on, people are increasingly concerned about the use of chemical pesticides.The low toxic and safe chemical pesticides and highly efficient and stable biologicalpesticides will become the trend of development in future. Biological control as the mostpotential control method is popular.Fungal polysaccharide is a natural polymer compound, which widely present in fungi,particularly in the cell walls of large fungi. It is a beta-type polysaccharide, which is named as"biological response modifiers (biological response modifier)”. A growing number of studieshave shown that, the chitosan amino Oligosaccharins and mushrooms proteoglycan not onlyhas the role of suppressing fungi, bacteria and viruses, but it also can adjust the growth ofcrop, induce plant resistance. Meanwhile, it is non-toxic, susceptible to degradate, non-pollution to the environment, which makes it possible to play an important role in agriculturalproduction as a new type of green pesticides.We used Chenopodium amaranticolor and tobacco NC89as test material. The half ofnecrotic lesions and pot experiment were used to measure the effect of10species of fungipolysaccharides on inhibiting CMV and the effect on the growth of tobacco. Then we filteredout C. verscicolor polysaccharide as the most inhibitory on the cucumber mosaic virus(CMV), and further determined the Field Efficacy of C. verscicolor polysaccharide on CMV.The research provides an effective way and theoretical basis for new biological antiviral agents.After two years of testing and analysis, we get the conclusions that:1、The polysaccharide of Coriolus versicolor、Hericium erinaceus、Marasmiusandrosaceus、Grifola frondosa、Ganoderma lucidum、Polyporus umbellatus、Auriculariaauricular、Cordyceps sinensis、Lentinus edodes and Armillariella mellea have a certain degreeof inhibition on CMV. Different concentrations of fungi polysaccharide on the CMV havecertain inhibition. The inhibition effect is improved with the increase of concentration offungi polysaccharide. In different treatments, the prevention effect is the best, followed bydeactivating effect. The C. verscicolor polysaccharide of1000mg/L has well preventing effect(79.83%) on CMV.2、The10kinds of fungi polysaccharides also promote the growth of tobacco. The effectof C. verscicolor polysaccharide is the most efficient. Plant height, stem girth, fresh weightand leaf area are higher than CK respectively87.37%,48.28%,58.03%and222.27%.3、The field efficacy trials indicate that the C. verscicolor polysaccharide shows highercontrol effect to CMV for a long time. After spraying C. verscicolor polysaccharide7,14and21d, the control effect were respectively74.30%,68.07%and62.03%. The control effect isbetter than ningnanmycin and virus A.In short, the C. verscicolor polysaccharide as a green, safe and biologically activesubstance, not only shows good control effect on CMV, but also is safety to the environmentand human health. It is in line with the trends of pesticides development, and has good value.