Studies On Screening Marine Actinomycetes And Agricultural Bio-Activity

From 14 samples in sea, 115 strains of marine actinomycetes were obtained. From the screening of the insecticidal, fungicidal and herbicidal activities, we found 3 strains of actinomycetes numbered A₂,E₃ and I₁₀ ,the metabolites of which had strong fungicidal activities. The main results are as follows:1. The fermentation products of A₂ had 85% control effects against Alternaria solani,Fusarium graminearum,Bipolaris maydis,Macrophoma kawatsukai,Bipolaris sorokiniana,Alternaria longipes,Fusarium oxysporium,Fulvia fulva; fermentation products had 98.30%,96.06% and 88.33% control effects against Exserohilum turcicum,Alternaria longipes and Curvulavia lunata respectively. By means of the double-layer method, the test exhibited that the diameter had 26.7mm,28.5mm and 20.2mm to Bacilluscereus,Staphylococcus aureus and Escherichia coli respectively. The results of pot tests showed that the fermentation products exhibited 98.31% of protective efficacy and 91.56% of therapeutic efficacy against Pseudoperonospora cubensis.2. The fermentation products of E₃ had 85% control effects against Fusarium graminearum,Bipolaris maydis,Macrophoma kawatsukai,Bipolaris sorokiniana,Valsa mali and Fulvia fulva;the fermentation products had 93.41%,91.12% and 70.97% control effects against Exserohilum turcicum,Alternaria longipes and Curvulavia lunata respectively. By means of the double-layer method, the test exhibited that the diameter had 21.5mm,27.1mm and 23.3mm to Bacilluscereus,Staphylococcus aureus and Escherichia col i respectively. The results of pot tests showed that the fermentation products exhibited 91.56% of protective efficacy and 83.97% of therapeutic efficacy against Pseudoperonospora cubensis.3.The fermentation products of I₁₀ had 85% control effects against Alternaria solani,Fusarium graminearum,Bipolaris maydis,Macrophoma kawatsukai,Bipolaris sorokiniana,Valsa mali,Alternaria longipes and Cercospora sorghi; the fermentation products had 65.77%,90.44% and81.65% control effects against Exserohilum turcicum,Alternaria longipes and Curvulavia lunata respectively. By means of the double-layer method, the test exhibited that the diameter had 22.7mm,23.9mm and 19.7mm to Bacilluscereus,Staphylococcus aureus and Escherichia coli respectively . The results of pot tests showed that the fermentation products exhibited 99.57% of protective efficacy and 75.53% of therapeutic...