老鼠簕真菌病病原的分离鉴定及生物学特性

Isolation,Identification,and Biological Characteristics of a Fungal Pathogen on Acanthus ilicifolius

【目的】明确老鼠簕(Acanthus ilicifolius)叶斑病的病原种类及其生物学特性。【方法】从福建省漳江口红树林国家级自然保护区采集病叶,采用离体组织分离法对病叶病原菌进行分离,采用形态学与分子生物学(ITS和EF1-α基因序列分析)的方法鉴定其病原菌种类,并对该病原菌的菌丝在不同温度、pH、碳源和氮源等条件下的生物学特性进行研究,以及对过氧化氢酶(CAT),超氧化物歧化酶(SOD)、过氧化物酶(POD)、漆酶、纤维素酶(CL)、β-葡萄糖苷酶(β-GC)进行活性检测。【结果】经鉴定该病原菌为真菌界子囊菌门镰刀菌科的轮枝镰刀菌(Fusarium verticillioides)。这是轮枝镰刀菌侵染老鼠簕引发叶斑病的首次报道。生物学特性研究显示该病原菌生长的最适温度25℃,最适pH为10,最佳碳源为淀粉,最佳氮源为酵母粉。3种氧化还原酶中,过氧化物酶(POD)活性最高;3种水解酶中,纤维素酶(CL)活性最高。【结论】分离鉴定了福建省漳江口老鼠簕叶斑病病原菌为轮枝镰刀菌(Fusarium verticillioides),明确了病原菌的生物学特性。

【Objective】Pathogen of the leaf spot disease on Acanthus ilicifolius was isolated and identified with its biological characteristics determined.【Method】Microbes were isolated from the diseased A.ilicifolius leaves collected from the Zhangjiangkou Estuary Mangrove National Nature Reserve in Fujian Province by the detached tissue method.Morphological and molecular biological techniques including ITS and EF1-αgene sequence analysis were employed to identify the pathogen.Optimal growth conditions of the identified fungus with respect to temperatures,pH,carbon sources,and nitrogen sources,in addition to its activities of catalase(CAT),superoxide dismutase(SOD),peroxidase(POD),laccase,cellulase(CL),andβ-glucosidase(β-GC)were determined.【Result】For the first time Fusarium verticillioides in the Ascomycota phylum was identified as the responsible pathogen of the disease.It thrived at 25°C and pH 10 on a medium using starch as carbon source and yeast powder as nitrogen source.POD was the oxidoreductase,and CL the hydrolase,that showed the highest activity in the fungus.【Conclusion】The pathogen that caused the leaf spot disease on bougainvillea in the Zhangjiang Estuary was identified as F.verticillioides.The biological characteristics of the strongly adaptable fungus were determined.