红斑病是牡丹种植上常见的病害。在我国四川、河南、江苏、浙江、北京、上海、西安等地均有发生。病菌主要侵染叶片,也可侵染茎、花及花冠、果实和种子。初期症状为新叶背面出现绿色针头状小点,后扩展成紫褐色近圆形小斑,有不太明显的轮纹,许多小的病斑 Red spot is a common disease on peony cultivation. In China, Sichuan, Henan, Jiangsu, Zhejiang, Beijing, Shanghai, Xi’an and other places have occurred. The main bacteria infected leaves, but also can infect stems, flowers and corolla, fruit and seeds. The initial symptoms of new leaves appeared on the back of the green needle-shaped dots, expanded into purple-brown sub-circular small spots, there are less obvious round pattern, many small spots