| Suodou disease of Strawberry is a serious disease which currently restricted "Strawberry in shuangliu in winter" industrial development. In serious illness field it cuts production by more than50%.It directly impacts on farmers’income and the improvement of living standards. In this thesis, the "shrinking root disease" which is very prominent in Shuangliu County strawberry production area in recent years was diagnosed.The cause of the disease was identified as pathogens of Fusarium oxysporum.Thus " Suodou disease " was diagnosed as strawberry Fusarium Wilt. On this basis, the biological characteristics of bacteria were clarified.The study on prevention and treatment of diseases is another important element of this paper.Two inhibition agents that inhibited the fungicides significantly were screened out.Through the field control test,chloropicrin fumigation of soil is effective in controlling the disease.Biological characteristics of pathogenic bacteria:pathogenic bacteria in the PDA, PSA arising from aerial hyphae than in several other medium thick, PDA, PSA medium most suited to the culture and their determination. Growth of strains in weak acidic environment better, optimal pH between6-7, mycelium grow faster when the pH value is within the scope of4-7.5, and when pH values is less than3or more than8, the mycelium growth significantly inhibited. Growth of mycelia40℃range can, as temperatures rise, growth rate accelerated, optimal temperatures of30℃.Best temperature range in25-30℃is the growth of Fusarium oxysporum, under different light conditions, influence on Mycelial growth of Fusarium oxysporum rate no significant different. Effects of different nitrogen sources and carbon source hyphal growth and sporulation of best carbon source is maltose, fastest-growth of potassium nitrate as nitrogen sourceSporulation of pathogenic bacteria are not demanding, mycelium growth characteristics are unlikely, but alternating light-dark conditions can promote the Fusarium oxysporum fungus spore. Pathogens in pH to neutral or acidic environment, best for sporulation, Spore largest, too acid or too alkaline environment is not suitable for sporulation of Fusarium oxysporum fungi. Most suitable for production of temperature of30℃, of sucrose as the carbon source the most appropriate. By diameter of the test using the colony determination fludioxonil, azoxystrobin, tebuconazole, hymexazol, three of ketones, carbendazim of6fungicides on Fusarium oxysporum bacteria in different concentrations of inhibition, fungicides screening of FLUDIOXONIL and highest inhibition of azoxystrobin, EC50, respectively0.3082μg/ml and0.3725μg/ml, toxicity are the commonly used reagents carbendazim (EC50for60.2701μg/ml)195.55times and three times, finally selecting fludioxonil, azoxystrobin, tebuconazole, field trial of hymexazol as a medicamentBased on the results of field experiments, can be found using the induced resistance can raise seedling of Strawberry’s own ability to resist disease, reducing the hazards of pathogens. Fludioxonil and Azoxystrobin can effectively inhibit the growth of pathogenic bacteria, has a good effect. Chloropicrin fumigation community has better control of Strawberry Fusarium wilt, in controlling soil-borne diseases of many reagents should belong to the best in the Pharmacy.The papers on the production base of Strawberry in shuangliu County is very prominent in recent years "shrinking root disease" diagnosis, clear of the diseases caused by pathogens of Fusarium oxysporum(Fusarium oxysporum), thus "reducing root disease" diagnosis of Fusarium wilt of strawberry. And on this basis, identify the biological characteristics of the pathogen. Another important element of this is a study on the prevention and treatment of diseases of the, filters out the two kinds of fungicides on the inhibition of bacteria significantly. At the same time after field testing, proof of chloropicrin fumigation of soil can effectively control the disease. |
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