【摘要】 <正> 一、前言 山杨灰斑病广泛发生在黑龙江、山东和新疆各地,对山杨为害很大。1983年在黑龙江省林口县青山林场山杨次生林中的幼树上发现有灰斑病。该病主要为害幼树幼苗的嫩梢和叶片,严重时嫩梢枯顶正株叶片枯死。 在野外调查的基础上,进行了病原菌的分离培养、病原菌的生物学特性、病原菌的更多还原

【Abstract】 A new infecting leaf spot disease of Populus davidiana has been found in Heilongjiang province of the northeast of China. It is identified as the pathogenic fungi-Spiloeacea sp. The conidia are brown, most of which are dispore, club-shaped to club-pyriform, and whose sizes are around 16.31—23.75×6.28-6.81μm(400x); the condiophore is brown, one apore, single growth or gregarious, on top of which there are two annellides.They also affect Populus alba var. pyramidalis Bunge, P. albax P. davidiana, P. albax P. sacran. The pathogen infect host through stomata and wounds, the dormant period is 13—15 days. The conidia of the pathogen can germinate well in waterdrop; the optimum pH is 6.0—6.6; conidia on the poplar leaf extract and glucose agar midium germinate to the maximum about 93.5 percent. The c0nidium grow on the PDA pathogen in 15 days.更多还原