新疆南部塔河流域柳树腐烂病病原菌的鉴定

摘要

[Objective] Through the study on pathogenic bacteria culture morphology and shape observation,combined with analysis of molecular biology techniques ITS and β-tubulin sequence analysis,this project aims to make clear how many kinds of willow valsa cander pathogens there are and their genetic differentiation in southern Xinjiang.[Method] Willow valsa cankers pathogen was collected and pure culture of pathogen was obtained.The conidia of the pathogen of pathogenic bacteria were divided into longitudinal and vertical sections and the morphological data were observed.Using ITS and β--tubulin sequence analysis method,the phylogenetic tree was successfully constructed.The most optimum pathogen was studied after β-tubulin sequential analysis.[Result] The pycnidium and conidia characteristics were consistent with the reported Cytospora chrysosperma.The most optimum conditions for the growth of pathogenic bacteria were the temperature between 20℃-30 ℃,the PH was 5-6,and the suitable carbon and nitrogen sources were glucose and peptone,respectively.ITS and β-tubulin analysis showed the sequence was up to 96％ identical with Cytospora spp.;Pathogenic bacteria could infect 5 kinds of trees successfully in the in vitro inoculation conditions.[Conclusion] Biological observation and molecular sequence analysis showed that the pathogen causing willow valsa cankers in Tarim River basin of southern Xinjiang is Cytospora chrysosperma.There are some genetic differentiations among pathogens from different sources.These pathogens can infect poplar,populus euphratica,jujube tree,pear and apple,and produce conidia in populus euphratica and poplar inside the room.%[目的]通过对病原菌形态学和培养形状观察,结合分子生物技术ITS和β-tubulin序列分析,明确新疆南疆柳树腐烂病菌种类和遗传分化.[方法]采集柳树腐烂病并获得病菌纯培养,对腐烂病菌分生孢子器进行纵横切片并观察记录形态数据,将病原菌置于不同营养条件和环境条件下观察记录其培养形状,采用ITS和β-tubulin序列分析方法结合,构建系统发育树.[结果]分子孢子器和分子孢子形态特征与金黄壳囊孢菌(C.chrysosperma Per.ex Fr.)一致;菌丝生长最适温度20～30℃,最适pH值为5～6,最适碳氮源分别是葡萄糖和蛋白胨;经β-tubulin序列分析,与壳囊孢属不同种类的序列相似度为96％以上;在室内离体接种条件下病原菌均能成功侵染其他5种树木.[结论]引起新疆南部塔河流域柳树腐烂病原菌为金黄壳囊孢菌(C.chrysosperma per.ex Fr),不同来源的病原菌存在一定的遗传分化,在室内可侵染杨树、胡杨、枣树、梨和苹果,并可在胡杨和杨树上产生分生孢子器.