桃叶蓼白粉菌的显微观察及进化关系分析

研究旨在通过对桃叶蓼白粉病的显微观察和进化关系的分析来鉴定该病原菌的种类和寄主范围,为桃叶蓼白粉病的防治提供合理依据。以桃叶蓼上发生的白粉病菌为试材,采用显微观察法对桃叶蓼上的白粉菌分生孢子、子囊、子囊孢子等进行形态观察和描述;使用试剂盒法提取桃叶蓼白粉菌DNA并进行ITS扩增。经过显微观察发现,桃叶蓼白粉菌分生孢子呈柱形;子囊果呈暗褐色,多数聚生或者近聚生,多呈扁球形;子囊多数呈各种不规则卵形,其中多含2~4个椭圆形子囊孢子,结合与其他白粉菌进行碱基序列比对和亲缘关系分析,确定该菌种与GenBank中的Polygonum aviculare（登录号为LC328322.1）、Polygonum erectum（登录号为KX826856.1）之间的亲缘关系最为接近,碱基序列相似度值达到99%,初步判定桃叶蓼白粉病病原菌与这两种菌种为同种同属。

The Powdery Mildew on Polygonum persicaria L.: Microscopic Observation and Phylogenetic Relationship Analysis

The purpose of the study is to identify the species and host range of powdery mildew on Polygonum persicaria L. by microscopic observation and phylogenetic relationship analysis, and to provide a reasonable basis for the control of powdery mildew. The powdery mildew on P. persicaria was used as test material. The conidia, ascus and ascospore were morphologically observed and described by microscopic observation. Genome DNA of the pathogen was extracted by kit method and amplified by ITS. The microscopic observation showed that the conidia of powdery mildew on P. persicaria were columnar. The asci were dark brown, mostly aggregated or near aggregated, and most of them were oblate spherical. Most of the asci were in various irregular oval shapes, containing 2 to 4 oval ascospores. Combined with other powdery mildew base sequence alignment and the analysis of genetic relationship, the powdery mildew on P. persicaria was confirmed to have the closest genetic relationship with Polygonum aviculare (LC328322.1) and Polygonum erectum (KX826856.1) from GeneBank, the sequence similarity was up to 99%. It was preliminarily determined that the pathogen of P. persicaria powdery mildew belonged to the same genus with these two species.