大樱桃黑斑果腐病菌生物学特性研究

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

大樱桃黑斑果腐病是辽宁大樱桃产区发现的一种新病害,近年在辽宁大樱桃产区为害严重,对该病进行了病原鉴定及生物学特性研究,以期明确其病原及适生能力,从而为该病害的田间流行规律和防治研究提供理论基础。利用不同条件对菌丝生长和孢子萌发情况进行测定,结果表明:病菌在光照条件下生长情况良好,最适生长温度为30℃,生长最适pH值为6.0。燕麦培养基对菌丝生长最有利,菌落直径可达8.9 cm;胡萝卜培养基最利于产孢,产孢量可达4.52×106个.mL-1。适宜该菌生长的碳源为果糖和蔗糖,氮源为硝酸钾。该菌孢子萌发最适温度为30℃,最适pH值为7.0,最佳碳源为木糖,最佳氮源为磷酸二氢铵。病原菌菌丝致死温度为56℃、10min。大樱桃黑斑果腐病菌适生条件较为宽泛、分生孢子萌发能力较强,与田间发病情况较为吻合。

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~C 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 4.52x106mL-＇. 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 rain. 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.