甘肃省当归霜霉病病原鉴定  

Identification of the pathogen causing downy mildew in Angelica sinensis in Gansu Province

作　　者：朱倩丽 何翔 张洋洋 聂江山 王常清 芦光新[1] ZHU Qian-li;HE Xiang;ZHANG Yang-yang;NIE Jiang-shan;WANG Chang-qing;LU Guang-xin(College of Agriculture and Animal Husbandry,Qinghai University,Xining 810016,China;Gansu Yasheng Agricultural Research Institute Co.,Ltd.,Lanzhou 730030,China)

机构地区：[1]青海大学农牧学院,青海西宁810016 [2]甘肃亚盛农业研究院有限公司,甘肃兰州730030

出　　处：《草业学报》2024年第7期142-150,共9页Acta Prataculturae Sinica

摘　　要：为明确引起兰州市榆中县当归霜霉病的病原菌并为该病害的田间诊断和防治提供理论依据,本研究通过田间病害症状识别、病原显微形态的观察与记录,初步鉴定病原菌种类;收集病株上病原菌的菌丝,提取DNA,扩增28S rDNA D1/D2区序列和线粒体DNA(mtDNA)基因cytochrome c oxidase subunit Ⅱ(cox2)序列并进行测序,根据测序结果分别构建系统发育树分析病原菌种类。经调查,该病害主要危害叶片,初发病时叶正面表现为不规则褪绿斑,斑点后有白色霜状霉层,后褪绿斑逐渐变为褐色枯死斑,严重时整株死亡;显微观察到的病原菌孢囊梗及孢子囊与已有资料中的当归轴霜霉形态一致;序列比对得出病原菌的28S rDNA D1/D2区序列与轴霜霉属Plasmopara pimpinellae HV 634同源性达99.87%,cox2基因序列与轴霜霉属P.pimpinellae TCM-155同源性达100%;系统发育树显示,侵染伞形科植物的轴霜霉属菌种聚在一个分支,亲缘关系密切,与侵染其他不同科寄主植物的轴霜霉亲缘关系较远。28S rDNA D1/D2区序列和cox2基因序列分子鉴定结果一致,均显示与轴霜霉属P.pimpinellae亲缘关系最近,其寄主与当归都是伞形科植物,结合形态学鉴定,确认当归霜霉病的病原菌为Plasmopara angelicae;本研究系国内当归霜霉病病原菌首次系统报道。The aim of this work was to identify the pathogen causing downy mildew in Angelica sinensis in Yuzhong County,Lanzhou City,to provide a theoretical basis for field diagnosis and control of the disease.The pathogen was preliminarily identified by recording disease symptoms and by observing its morphology under a microscope.Hyphae were collected from diseased plants and the DNA was extracted.The 28S rDNA D1/D2 region and the mitochondrial DNA(mtDNA)gene cytochrome c oxidase subunit Ⅱ(cox2)were sequenced,and phylogenetic trees were constructed based on the sequencing results.The disease primarily affected the leaves.At the onset of the disease,irregular chlorotic spots appeared on the front side of the leaves,followed by the development of a frosty white mildew layer.Eventually,the chlorotic spots became brown dead spots,and in severe cases,the entire plant died.The morphology of the sporangiophores and sporangia were consistent with those of Plasmopara angelicae.The 28S rDNA D1/D2 region displayed 99.87% sequence similarity to that of Plasmopara pimpinellae HV 634,while the cox2 gene exhibited 100% sequence similarity to that of P.pimpinellae TCM-155.Phylogenetic analysis revealed that the Plasmopara species infecting Apiaceae plants were clustered together and were more distantly related to Plasmopara species infecting host plants from different families.Molecular identification based on the 28S rDNA D1/D2 region sequence and cox2 gene sequence corroborated the close relationship between the pathogen and P.pimpinellae that parasitizes members of the Apiaceae.Additionally,morphological identification confirmed the downy mildew on A.sinensis as P.angelicae,consistent with the membership of A.sinensis in the Apiaceae family.This study is the first comprehensive report on the pathogen responsible for downy mildew in A.sinensis in China.

关 键 词：当归 霜霉病 形态学特征 系统发育关系 当归轴霜霉 

分 类 号：S435.672[农业科学—农业昆虫与害虫防治]