牡丹腔孢叶斑病及其病原物的共无性型

牡丹腔孢叶斑病于2007-2008年在山东省菏泽、济南、泰安、肥城等地牡丹上普遍发生,除危害牡丹叶片外,也发生于枝干上,在病枝上形成边缘褐色、中部灰白色的病斑,病斑绕茎可致枝条干枯,于病部形成稀疏的黑色扁平状子实体;叶片上病斑黄褐色,圆形至长圆形,直径10-35mm,具褐色至黄褐色相间的同心轮纹,于其上形成橘黄色至橘红色子实体。叶斑上的病原物载孢体盘状、有柄,为Hainesia lythri;病枝上的病原物载孢体为封闭的半球形结构,显示Pilidium concavum的典型特征。两种载孢体中形成的产孢细胞及分生孢子形态一致。分别从多份牡丹病枝、叶上分离获得的7株和21株分离物,在培养性状、生物学特性和致病性等方面基本相似。依据上述特性及部分分离物的rDNA-ITS序列分析结果,将山东牡丹叶斑上的病原物鉴定为Hainesia lythri,病枝干上为Pilidium concavum。二者是同一病原真菌的共无性型。

The causal agent of coelomycete leaf spot of Paeonia suffruticosa and its synanamorphs

A new Paeonia suffruticosa leaf spot disease firstly reported by Zhang et al.from Henan Province was also observed on the same plants growing in Heze,Jinan,Tai'an and Feicheng etc.of Shandong Province in 2007-2008.The disease can also infect stems and branches of the plant to form grey-whitish and brown-margined spots on which a few black and flattened fructifications scattered.The conidiomata on leaf spots are cupulate whereas those on stem spots are semi-spherical and unostiolate.However,the morphology of the conidiophores,conidiogeneous cells and conidia in these different types of conidiomata are very similar.The 7 isolates from stem spots and 21 ones from leaf spots are also similar in cultural and biological characteristics as well as pathogenicity.Based on morphological observation and rDNA-ITS sequence analysis,the pathogen on leaf spots was identified as Hainesia lythri,while that on stem spots as Pilidium concavum.They are synanamorphs of the same fungus Discohainesia oenotherae.