Biological Characteristics of Black Fruit Rot Caused by Alternaria alternata on Cherry

Black fruit rot disease on cherry fruits in Liaoning occurs seriously in recent years.Biological characteristics of the pathogen were studied to find the suitable condition of the pathogen and for disease epidemic,and help its control in the field.The mycelia growth and spore germination were determined under different conditions.The test revealed that the suitable conditions for mycelia growth were light,30℃ and pH 6.0.Oat medium was the best for mycelia growth and the colony diameter was 8.9 cm,carrot-ager was the best for sporulation and the number of spore was 4.52×106mL-1.The carbon sources of fructose and sucrose were best for mycelia growth,among nitrogen sources,KNO3 was the best.In light of spore germination,the optimal temperature was 30℃,the optimal pH was 7.0,xylose was the best carbon source,NH4H2PO4 was the best nitrogen source.The lethal temperature for mycelia growth was 56℃ for 10 min.The pathogen had a broad condition for live and a high capacity for spore germination which were consistent with the occurrence of the disease in the field.