Study On The Biological Characteristics Of Anthracnose And Leaf Spot In Jingyang And The Prevention And Control Of Medicament Screening

In this experiment,samples of anthracnose and leaf spot diseases were collected in Jingyang county,and two pathogenic bacteria were isolated by conventional separation method.The biological characteristics of the two pathogens were studied respectively.Six chemical agents were selected to determine the toxicity of the two pathogens,and the drugs with high toxicity were selected.The main results of this study were as follows:Two pathogenic bacteria were isolated from disease samples by conventional tissue separation.The first pathogen was orange green,the mycelia were dense and the growth rate was moderate.The meridional spores were long elliptic,the size was(7.8 ~ 16.7)um,and(2.6 ~ 5.0)um.According to Sutton's classification system,the pathogen was identified as colletotrichum acutatum.The second pathogen was dark brown,developed aerial hyphae is pale in color.The spores were ovate,elliptic,and anguilliform,with 1 ~ 8 diaphragms and 0 ~ 4 mediastinum.Compared with Chinese fungi,it was identified as the pathogen of Alternaria.The results of pathogenicity identification indicated that: the isolated pathogen was same,and the both pathogens are pathogenic.The biological characteristics of two pathogenic bacteria under different light,temperature,p H and carbon nitrogen were studied by cross-crossing method and blood count plate method.Anthracnose pathogen in 24 h full illumination,temperature 25?,p H value of 6,carbon source is glucose,nitrogen source for tryptone under the condition of optimum pathogenic bacteria to grow;Within 24 h full illumination,temperature 25?,p H value of 5,carbon source for maltose,nitrogen source for tryptone under the condition of optimum pathogen spores.Leaf spot pathogens in 24 h full illumination,temperature 30?,p H value of 6,carbon source for soluble starch,nitrogen source for tryptone under the condition of optimum pathogenic bacteria to grow.Within 24 h full illumination,temperature 30?,p H of 6,carbon source is glucose,the optimum nitrogen source for tryptone conditions pathogen spores.Six chemical agents were selected to determine the indoor toxicity of the two pathogens respectively by using the growth rate method.The inhibitory effect of 25% Tebuconazole was the best in the determination of anthracnose,and the EC50 was 0.41?g/mL.;the bacteriostatic effects of pyriloxonitrile,62% Cyprodinil plus fludioxonil,25%Pyraclostrobin,10% Difenoconazole and 30% Difenoconazole plus propiconazole were also very good,the EC50 were 3.53?g/mL,4.61?g/mL,2.12?g/mL,1.48?g/mL respectively;The bacteriostatic effect of 56% Azoxystrobin plus chlorothalonil was the weakest,while the EC50 was 135.41?g/mL.The inhibitory effect of 62% Cyprodinil and fludioxonil was the best in the determination of phyllostasis,and the EC50 was 6.59 ?g/mL.The inhibitory effect of 50% Iprodione and 10% Difenoconazole were also good,EC50 were 24.42?g/mL and 10.58?g/mL;the inhibitory effect of 72% Cymoxanil plus mancozeb was relatively general,and the EC50 was 381.99?g/mL;the inhibitory effect were the weakest of 56% Azoxystrobin and chlorothalonil and 70% Propineb,and the EC50 was 1392.49?g/mL and 1324.70?g/mL.