杨树水泡型溃疡病的发生及病原菌生物学特性的研究

 杨树水泡型溃疡病分布广泛,严重为害杨树。分生孢子是主要的侵染源。病菌由伤口、皮孔或表皮侵入寄主。每年5~6月为春季发病高峰,9月为秋季发病高峰,秋季发病较春季为重。孢子的飞散高峰在8~9月。病害的消长与降雨量和相对湿度密切相关,雨季孢子飞散较多,分生孢子萌发的最适温度为25~30℃,子囊孢子萌发的最适温度为20~30℃。分生孢子萌发要求水分,在黑暗下发芽率高。病原可潜伏侵染,一般在2~3年生枝干上侵染较多,7~9月是潜伏侵染的高峰。除杨树外,还能为害多种阔叶树。病原在麦芽糖和蛋白胨培养基中菌丝生长较旺盛,在蔗糖和硝酸钾培养基中有利于分生孢子器形成,杨树树皮汁液能促进分生孢子发芽。

ON THE OCCURRENCE AND BIOLOGICAL CHARACTERS OF A POPLAR BLISTER CANKER

The blister canker on poplar trunks causd bg Botryosphaeria dothidea arewidely distributed in North China. The main inoculum of infection are conidia. The infections are through wounds,lentical and epidermis.Occurring mostly from May to June and also in September. The disease is more serious in autumn than in spring. Spore dispersion took place in August and Septermber. The ocurrence of this disease is closely related to rain fall and relative hu midity. Spores are disseminated rapidly in rainy season. The optimum temperature for conidia germination ranged from 25-30℃ while the optimum temperature for ascospore germination is from 20 to 30℃:Germination rate is higher in light than in dark.
The pathogen may survive in a state of latent infection in 2-3 year aged branches or stems.The high peak of spore dissemination is in Julyto September.