| Abstract:Objective: The aim of this study was to characterize the biology of Corynespora cassiicola, the pathogen of septoria leaf spot of Scutellaria baicalensis, and to screen agents for efficient control of this disease, so as to provide theoretical guidance for the cultivation and production of S. baicalensis. Methods: The influences of different carbon and nitrogen sources, culture medium, temperature, pH value and lighting conditions on C. cassiicola and the toxicities of five commercial fungicides against C. cassiicola were examined using mycelial growth rate method. Results: The optimal growth conditions for C. cassiicola are carrot medium amend with soluble starch and sucrose as carbon sources, peptone as nitrogen source, pH6, 30℃, and cultivate in dark. 98% carbendazim shown the strongest toxicity against C. cassiicola, with an EC50 value of 0.07 mg?L-1; follows by 98% fludioxonil, 98% prochloraz and 98% pyraclostrobin, with the EC50 values of 0.10 mg?L-1, 0.18 mg?L-1 and 3.06 mg?L-1; the toxicity of 98% azoxystrobin to C. cassiicola was the weakest, with the EC50 values of 632.39 mg?L-1. Conclusions: C. cassiicola has a wide range of fitness, it could grow under a variety of carbon and nitrogen sources, culture medium and pH conditions, neutral to weak acid and higher temperature conditions are conducive to its rapider growth. Carbendazim and fudioxonil showed strong inhibitory effects on C. cassiicola, and these two fungicides can be used to control Septoria leaf spot on S. baicalensis in the field. |
