车前草白粉病的病原菌鉴定

Identification of Plantago asiatica Powdery Mildew

为了探明河南商丘地区车前草白粉病病原菌的系统进化关系,为其防治提供理论依据,采用形态学、致病性、分子系统学鉴定方法对该地区的车前草白粉病病原菌进行鉴定。结果表明:1)商丘地区车前草白粉病病原菌的分生孢子呈近柱形或桶形,无纤维体,大小为(25～36)μm×(13～17)μm,3～5个串生;分生孢子梗稍弯曲,无分枝,大小为(149～215)μm×(11～16)μm,其脚胞呈柱状,大小为(45～64)μm×(10～15)μm;病原菌接种叶片与自然状态叶片的病症相似,均为不定形的污白色斑。2)对核糖体DNA内转录间隔区(ITS)序列进行PCR扩增、测序获得594bp目的片段(GenBank登录号:JQ 845878),经MEGA3.1软件序列分析发现其与来自污色高氏白粉菌(Golovinomyces sordidus)的AF 011309、AB077658序列聚为1枝,而与来自同属另3个种的ITS序列的亲缘关系较远。结论:河南省商丘地区的车前草白粉病病原菌为G.sordidus。

In order to make clear the phylogenetic evolution relationships of powdery mildew detected in P. asiatica in Henan Shangqiu of China and provide a theoretical basis for its control, P. asiatica powdery mildew was analyzed by morphological, etiological and molecular systematics identification. The results show that： 1） Conidia of pathogenic bacteria are cylindricality or doliform, without fibrosin dodies, with the sizes of （25 - 36）μm× （13 -17）μm, three to five in chain; conidiophores are simple structure with no branches, of （149-215）μm × （11-16）μm and foot cells are columnar, with sizes of （45-64）μm× （10-15）μm. Pathogenicity of inoculated leaves has no differences with leaves in natural state in formation of amorphous dirt white patch. 2） Internal transcribed spacer （ITS） sequence of its ribosomal DNA was amplified by PCR and sequenced to obtain the 594 bp target fragment （GenBank： JQ845878）, and sequence analysis by MEGA3. 1 software reveals this ITS sequence and two sequences from Golovinomyces sordidus（ GenBank： AF011309,AB077658） gather together, distantly related to the ITS sequences of other three species in the same genus. Conclusion： Pathogen of P. asiatica powdery mildew in Shangqiu is G. sordidus.