龙须藤茎皮甲醇提取物生物活性初探

龙须藤Bauhinia championii在医用方面已证实具有良好的抗菌、消炎作用,但其在农用方面的活性研究还鲜有报道。本研究分别采用菌丝生长速率法和种子生物测定法,首次测定龙须藤茎皮甲醇提取物及分离组分对6种农业有害真菌和单、双子叶两种植物的生物活性。结果表明,龙须藤甲醇浸提物对水稻稻瘟病菌Magnaporthe oryzae有一定的抑制效果,对油菜Brassica napus和稗草Echinochloa crusgalli的根芽均没有抑制作用。但其甲醇浸提物中分离的大部分组分对供试病原菌和植物的根芽都表现出一定抑制作用。杀菌活性方面:10号组分对西瓜枯萎病菌Fusarium oxysporum和番茄早疫病菌Alternaria solani的抑制效果最好,抑制率分别达到80.0%和78.0%,除草活性方面:1～3号组分对油菜根的抑制率较高,达到50%以上,2号组分对稗草根的抑制效果最好,达到68%。可见,龙须藤茎皮提取物中含有具有良好杀菌活性和除草活性的物质。

Biological activity of the methanol extract from Bauhinia championii

Bauhinia championii has excellent anti bacterial, anti inflammatory and other medical effects, but few studies have been reported on its agricultural biological activities. In this study, mycelia growth rate and seed bioassay methods were used to determine the bioactivities of the methanol extracts and separated components from B. championii against six species of agricultural pathogenic fungi and two weeds. The results showed that the methanol extracts had moderate inhibitory activity against Magnaporthe oryzae, and had no inhibitory effects on the root and buds of Brassica napus and Echinochloa crusgalli. However, some of the components isolated from the methanol extracts showed moderate inhibition against the tested pathogens, and the roots and buds of tested plants. In particular, component 10 showed the best inhibitory effect against Fusarium oxysporum and Alternaria solani, with an inhibition rate of 80.0% and 78.0%, respectively. The components 1-3 showed more than 50% inhibition rate against the root of B. napus. The component 2 had the best inhibitory activity against E. crusgalli, reaching 68%. The results provided a new idea for the development of new botanical pesticides.