现已证实杨树溃疡病的病原不是细菌,而是一种真菌Dothiorella gregaria Sacc.(有性阶段为Botryosphaeria ribis(Tode)Gross.et Dugg.)。自1973年以来,我们除了对该病进行人工接种外,同时还对病害的分布危害、病症病状、发病规律等方面作了调查研究和定点观察,现总结如下。一、分布危害杨树溃疡病分布于我国辽宁、黑龙江、山东、江苏、北京、陕西等省市。在陕西,1960年于西北农学院三道原林场的毛白杨幼树上首次发现,至今巳分布到西安、宝鸡、扶风、周 It has been confirmed that the pathogen of poplar canker is not a bacterium, but a fungus Dothiorella gregaria Sacc. (Sexual stage is Botryosphaeria ribis (Tode) Gross. Et Dugg.). Since 1973, in addition to the artificial inoculation of the disease, we have also made investigations and fixed-point observations on the distribution of the disease, the symptoms and the incidence of disease, and so on, and are summarized as follows. First, the distribution of hazards Poplar canker disease distribution in China’s Liaoning, Heilongjiang, Shandong, Jiangsu, Beijing, Shaanxi and other provinces and cities. In Shaanxi, the first discovery of young Populus tomentosa seedlings in the three primary forest farms of Northwest Agricultural College in 1960 has been distributed to Xi’an, Baoji, Fufeng, Zhou