鄂西北产猫眼草不同极性部位提取物抑菌活性评价

Evaluation on antifungal activity of different polar fractions of Enphorbia lunulata Bag obtained from Northwestern Hubei

【目的】探讨鄂西北产猫眼草对3种常见蔬菜病原真菌菌丝生长及孢子萌发的影响,以期为新型植物源杀菌剂开发提供一定的理论依据。【方法】以乙醇、甲醇、乙酸乙酯、氯仿4种有机溶剂依次对猫眼草全草进行浸提获得的提取物,分别采用生长速率法和孢子萌发法测定不同极性部位提取物对黄瓜枯萎病菌、大白菜灰霉病菌和辣椒白绢病菌菌丝生长和孢子萌发的抑制活性。【结果】除甲醇部对大白菜灰霉病菌、辣椒白绢病菌菌丝生长抑制作用较弱外,其他不同极性部位提取物均对3种病原真菌菌丝生长表现出明显的抑制活性,且抑制作用均随着提取物浓度的升高而增强,其中氯仿部对黄瓜枯萎病菌菌丝的抑制效果最好,EC50为0.007g/mL,乙酸乙酯部对大白菜灰霉病菌和辣椒白绢病菌菌丝的抑制效果最好,EC50分别为0.008和0.011g/mL。猫眼草不同极性部位提取物对3种病原真菌孢子的抑制作用均随着提取物浓度的升高而增强,其中甲醇部对3种病原真菌孢子的抑制作用相对较弱,乙酸乙酯部和氯仿部则明显较强,且氯仿部对黄瓜枯萎病菌孢子的抑制效果最好,EC50为0.005g/mL,乙酸乙酯部对大白菜灰霉病菌和辣椒白绢病菌孢子的抑制效果最好,EC50分别为0.005和0.004g/mL。【结论】猫眼草不同极性部位提取物对3种蔬菜常见病原真菌均具有一定的抑制作用,是一种潜在的、可用于生物杀菌剂开发的植物。

[Objective]Inhibitory effects of different polar fractions of Euphorbia lunulata Bag, collected from North- western Hubei, were observed on mycelial growth and spore germination in three vegetable pathogenic fungi in order to develop new plant fungicides. [Method ]The whole herb of E： lunulata was extracted with ethanol, methanol, ethyl acetate and chloroform. And the antifungal activity of these extracts to Fusarium oxysporum f.sp. cucumber Owen, Botrytis einerea Pers, Seletotium toffsii Sacc was investigated by detecting the mycelium growth rate and the spore germination. [Result] Except weak inhibitory effect of methanol extract on B. einerea and S. rollsii, other different polar fractions showed strong inhibitory activity which increased with increasing concentration of extracts. Chloroform fraction showed the highest inhibi- tion effects to F. oxysponum f.sp cucumber （EC50 for 0.007 g/mL） ; ethyl acetate fraction＇s inhibition effect was the highest in both the B. cinerea （EC50 for 0.008 g/mL） and S. rollsii （EC50 for 0.011 g/mL）. Inhibition of different polar fractions in E. lunulata on the above pathogenic fungi increased with increasing concentration. Similar inhibitory effects were observed in mycelial growth, that of methanol-extracting fractions were relatively weaker, but the fractions extracted with ethyl ac- etate and chloroform-extracting fractions were significantly stronger. The inhibitory efficiency of chloroform fraction to F. oxysporium f.sp cucumber （0.005 g/mL） was the highest; while both, the B. einerea （EC50 for 0.005 g/mL） and S. rolfsii （EC50 for 0.004 g/mL） the ethyl acetate fraction was the highest. [Conclusion]All the different polar fractions of E. lunulata had inhibition on the tested pathogenic fungi, hence E. lunulata can be used for bio-fungicide development.