| Fungal polysaccharide is a natural polymer compound,which widely present in fungi.Polysaccharde has been given more widely attentions for its function of antivirus,antitumor and immunomodular.Fungal polysaccharide is a beta-type polysaccharide,Many studies have shown that,it is not only has the role of suppressing fungi,bacteria and viruses,but it also can adjust the growth of crop,induce plant resistance.As a family of natural compounds,it is non-toxic,susceptible to degradate,non-pollution to the environment,which makes it possible to play an important role in agricultural production as a new type of plant elicitor.As one of the most important diseases in the production of tobacco leaf,Lots of researches has been made both at home and abroad and some progress had been made.Effective control of Tobacco virus disease are still lacking.As a kind of natural virus-fighting substance,natural virus-fighting substance,fungal polysaccharide are paid moreattention.The objective of this study was to explore the optimum culture condition and the optimum extraction method of Erenniporia fraxinea and Calvatia sp.and Mucor fuagil.Pot experiment and half leaf method was used in the experiment.In greenhouse tests,we analyzed the leaf area,fresh weight of leaves and roots,content of total chlorophyll and net photosynthetic rate of tobacco seedlings?Chinese cabbage and wheat after treated with fungal polysaccharide.The antiviral activity of polysaccharide on TMV were tested on tobacco seedlings of Nicotiana tabacum var.Samsun NN by half leaf method.The main research results are as follows:1?Measure the influence of different medium and extraction method on polysaccharide yield,The results show that soybean cake1%;yeast powder 0.2%;saccharose 3%;magnesium sulfate 0.05%;monopotassium phosphate0.1%;vitamin B1 0.01% is the best proportion of liquid medium.Wood chips 70%;wheat bran 27%;quick lime 1%;saccharose1% is the best proportion of solid medium.To compare the bioactive of fungal polysaccharide found the polysaccharide after liquid culture is superior to solid culture,water-bath extracting is superior to high-pressure extracting.2 ? Physio-chemical characters of polysaccharide are observed and measured,three kinds of polysaccharide are all dissolve easily in water but does not dissolve in organic solvents such as ethanol.The active ingredients of 3 kinds of polysaccharide were investigated by phenol-sulfuric acid and m-hydroxyldiphenyl and lowry method and Fehling method and found sugar content were 82.2%?84.9% and 65%;The amounts of uronic acid are0.87%?1.03% and protein are 1.37% respectively,but which are free of reducing sugars.3?Three kinds of fungi polysaccharide all have a good role in promoting the growth of smoke?chinese cabbage and wheat.As indicated in the results,the maximum leaf area and fresh weight of leaves increased 70.7% and 64.3% respectively after treated with polysaccharide of which concentration is 1000mg/L as compared with control.Total chlorophyll content and fresh weight of chinese cabbage increased 62.3% and 79.2% after treated with P.fraxinea polysaccharide of which concentration is 1000mg/L as compared with control.The seedling height and fresh weight of wheat increased 47.3% and 155.9% after treated with P.fraxinea polysaccharide of which concentration is 2000mg/L as compared with control.The other two polysaccharide also showed a good role in promoting the growth of smoke?chinese cabbage and wheat.4?The antiviral activity of polysaccharide on TMV were tested on tobacco seedlings of Nicotiana tabacum var.Samsun NN by half leaf method.Three kinds of fungi polysaccharide all have a good role in depressing the occurrence of virus disease,the depressing effect improved with the concentration increase.In all treatments,preventive effect of polysaccharide to TMV is the best,Followed by passivation effect.The infection rate of TMV reduced 74% when 2000mg/L Calvatia polysaccharide was applied before TMV inoculation. |
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