Biological control of intractable alien weed

早在19世纪初，日本虎杖就已经在英国种植了，但直到最近，这种植物才显示出它对城市发展的成本和对生物多样性的威胁。分布在英国的杂草是一种起源于日本的雌性克隆植物，因此寄主特有的物种具有很大的生物控制潜力。本研究的目的是调查杂草的天敌，特别是侵染杂草的植物病原真菌，鉴定收集到的植物病原真菌，并探讨潜在的植物病原真菌作为生物防治剂的可能性。结果表明，多goni- cuspidis Mycosphaerella是引起叶斑病的病原菌，是一种有效的生物防治剂。此外，从日本本土植物中分离出多种内生真菌。在这些分离株中，检测到疾病增强真菌。

Japanese knotweed has been in the UK since the early 19^<th> Century, but it is only in relatively recent times that the plant has shown itself to be a cost to urban development and a threat to biodiversity. The weed distributed in the UK is one female clonal plant originated in Japan, so species specific to the host hold a great potential to control this weed biologically. The objectives of this study were survey natural enemies, especially phytopathogenic fungi infected to the weed, identification of the collected phytopathogenic fungi, and investigation of possibilities of the potential phytopathogenic fungi as biocontrol agents. Mycosphaerella polygoni-cuspidati was identified as a causal pathogen of leaf spot disease, and evaluated as an effective biocontrol agent. Moreover, many kind of endphytic fungi were isolated from the Japanese native plants. Among these isolates, disease enhanced fungi were detected.