抑菌植物的筛选及甘草对5种植物病原真菌抑菌活性的研究

Studies on Screening of Antifungal Plants and Antifungal Activities of Glycyrrhiza uralensis Against Five Phytopathogens

为了寻找新的植物源杀菌剂,采用菌丝生长速率法测定了17种植物提取物对荔枝霜疫霉病菌Peronophythora litchi的抑菌活性.结果显示:辣蓼Polygonum lapathifolium、白花油茶Camellia oleifera甲醇提取物(干粉)10 mg/mL处理7 d后的抑菌率分别达74.37%、77.02%,而甘草Glycyrrhiza uralensis根甲醇提取物相同质量浓度时的抑菌率达到97.83%;甲醇对甘草的提取率为23.04%,甘草的甲醇提取物1和5 mg/mL处理对荔枝霜疫霉病菌菌丝生长的抑菌率分别为63.84%和80.68%,对荔枝霜疫霉病菌孢子囊芽管萌发的抑制中质量浓度(EC50)为0.47 mg/mL,对荔枝霜疫霉病菌、辣椒疫霉病菌Phytophthora capsici、芒果炭疽病菌Colletotrichum gloeosporioides、香蕉枯萎病菌Fusarium oxysporum f.sp.cubense和草莓叶斑病菌Cladosporium herbarum菌丝生长的EC50依次为0.62、0.89、9.70、6.42和4.53 mg/mL,表明甘草甲醇提取物具有较好的抑菌活性,有望继续研究开发成新的杀菌剂.

In order to find new fungicides, antifungal activities of 17 plant extracts against Peronophythora litchi were determined by using mycelial growth rate method. The main results were as follows： after 7 days＇ treatment with a dry-powder mass concentration of 10 mg/mL, the methanol extracts of Polygonum lapathifolium and Camellia oleifera showed inhibition rates of 74.37% and 77.02%, respectively, while the methanol extract of Glycyrrhiza uralensis（root） showed inhibition rates of 97.83% at the same test mass concentration; extraction ratio reached 20. 80% by using methanol to extract Glycyrrhiza uralensis （root） and it showed inhibition rates of 63.84% and 80. 68% on P. litchi with ally-powder mass concen- trations of 1.0 and 5.0 mg/mL, respectively, and the median inhibitory mass concentration was 0.47 mg/mL against the germination of sporangia of P. litchi. The median inhibitory mass concentration against P. litchi, Phytophthora capsici, Colletotrichum gloeosporioides, Fusarium oxysporum f. sp. eubense, and Cladosporium herbarum was 0.62, 0. 89, 9.70, 6.42 and 4.53 mg/mL, respectively. These results suggest that the methanol extract of G. uralensis （root） has good antifungal activity, and it is expected to develop into a new fungicide with further research.