植物病原真菌抑制杂草的活性筛选及菌株CY-H的活性代谢产物

Screening of herbicidal activities of plant pathogenic fungi and active metabolites of strain CY-H

摘要:

[目的] 分离并鉴定具有较好除草活性的植物病原真菌菌株，进一步分离活性化合物，为开发新型生物源除草剂奠定一定的基础。[方法] 采用固体培养基接种法分离纯化植物病原真菌，通过形态学特征观察和5.8S rDNA测序鉴定目标菌株；在活性筛选追踪下，对活性组分进行追踪分离及纯化，经波谱分析确定活性单体化合物结构；采用培养皿生物分析法测定活性单体化合物的除草活性及对常见作物的安全性。[结果] 茶叶致病菌CY-H具有较好的除草活性，其发酵液对稗草和反枝苋根的抑制率分别为94.6%和77.3%。CY-H被鉴定为间座壳属菌（Diaporthe sp.）。从CY-H菌中分离得到单体化合物CY1被鉴定为cytosporaphenones C。在供试浓度为100μg/mL时，CY1具有较好的抑制反枝苋根的活性，抑制率为57.1%，且其对小麦和油菜的安全性较好，抑制率均在20%左右。[结论] 茶叶致病菌CY-H具有开发成微生物源除草剂的潜力。

关键词:植物病原真菌;除草活性;间座壳属菌;cytosporaphenones C;天然产物

Abstract:

[Objective] The aim of this study was to isolate and identify plant pathogenic fungal strains with good herbicidal activity and to isolate active metabolites, for the development of new biological herbicides.[Methods] Phytopathogenic fungi were isolated and purified by solid medium inoculation. The targeted strain was identified by morphological observation and 5.8S rDNA sequencing analysis. The active components were separated and purified after screening and tracing, and the structure of the active monomer compounds was determined by spectral analysis. The herbicidal activity of active metabolite and its safety to common crops were determined by Petri dish biological analysis.[Results] Tea pathogen CY-H had good herbicidal activity. The inhibition rates of fermentation broth on radical growth of Echinochloa crusgalli and Amaranthus retroflexus were 94.6% and 77.3% respectively. CY-H was identified as Diaporthe sp.. The single compound CY1 was isolated from CY-H and identified as cytosporaphenones C. At the concentration of 100 μg/mL, CY1 had a good herbicidal activity against the A. retroflexus, with the inhibition rates of 57.1%, and it had a good safety against Triticum aestivum and Brassica napus with the inhibition rate of about 20%.[Conclusion] The tea pathogen CY-H could be potentially developed as a microbial herbicide.

Key words:phytopathogenic fungi;herbicidal activity;Diaporthe sp.;cytosporaphenones C;natural product