在陕西省杨树溃疡病(Dothiorella gregaria Sacc.)是一种严重的病害,分布普遍,危害130多个杨树品种、杂交种和无性系,其中有些树种如箭杆杨、北京杨、陕林2号杨、箭×钻杨等受害更为严重,常导致整株死亡,造成重大损失。据研究杨树溃疡病菌有潜伏侵染的特性,但在陕西省杨树苗木上未见其发病,有无潜伏侵染现象存在,更不清楚,为了弄清这一问题,我们于1987—1988年,对来自三个苗圃的24种杨树苗木 In Shaanxi Province, Dothiorella gregaria Sacc. Is a serious disease with widespread distribution and endangers over 130 poplar varieties, hybrids and clones, some of which are such as Populus alba, Poplar, Shaanxi No. 2 Yang, arrow × drilling Yang and other victims more serious, often lead to death of the entire plant, resulting in heavy losses. According to the study of poplar canker bacteria latent infection characteristics, but in Shaanxi Province poplar seedlings no incidence, with or without latent infection exists, it is not clear, in order to clarify this issue, we in 1987-1988 Year, 24 poplar seedlings from three nurseries