梨火疫病是一种在世界范围内分布、传播快、危害严重、防治困难的危险性病害,一旦传入,后患无穷。梨火疫病主要危害梨属、苹果属榅桲属、拘子属、山楂属、花揪属等32个属、140多种植物,尤以梨、苹果、山碴榅桲受害严重。病害多从叶缘开始发生,再沿叶脉扩展到全叶,先呈水渍状,后变黑褐色。嫩梢被害初期呈水渍状,随后变为黑褐色至黑色,常常曲向下,呈鱼钩状。枝、干受害初期是水渍状,而后皮层收缩,稍有下陷,形成溃汤疤,在病、健组织交界处出现龟裂,去掉皮层可以发现韧皮部呈 Pearly blight is a dangerous disease spreading around the world, spreading fast, endangering serious diseases and preventing and controlling difficult diseases. The main hazards of pear fire blight pear genus, apple genus genus, genus, genus Crataegi, genus and other 32 genera, more than 140 kinds of plants, especially pears, apples, bald razor clam severely affected. Disease occurs more from the leaf margin, and then extended to the whole leaf along the veins, first showed water stains, later dark brown. Tender shoots initially showed water stains, then turned black-brown to black, often song down, was hooked. The branches and stems were initially water-stained, and then the cortex contracted and slightly sagged to form ulcerative scars. At the junction of the diseased and healthy tissues, cracks were found and the cortex was removed and the phloem was found