皂荚提取物对植物病原菌的抑制作用

 豆科植物皂荚是一种传统药用植物,为我国特有种。本文在室内测定了皂荚叶和棘刺乙醇提取物对枯草芽孢杆菌、胡萝卜软腐欧文氏杆菌、番茄疮痂病菌、番茄灰霉病菌、番茄叶霉病菌、棉花枯萎病菌、瓜果腐霉的抑制作用。叶提取物未检测出抗菌活性。棘刺提取物对枯草芽孢杆菌和番茄疮痂病菌都表现出一定的抗菌活性,最低抑菌浓度(MIC)分别为2.5 mg/mL和10 mg/mL。棘刺乙醇提取物在浓度为1 mg/mL时,对4种植物病原真菌的生长都表现出抑制活性,其中对瓜果腐霉生长的抑制率为28.4%。将棘刺乙醇提取物分为石油醚等5个极性不同的萃取部分,其中乙酸乙酯部分对枯草芽孢杆菌、番茄疮痂病菌、欧文氏杆菌都具有明显的抑制作用,且活性强于其它的极性段,对枯草芽孢杆菌和番茄疮痂病菌的MIC分别为1.25 mg/mL和5 mg/mL。乙酸乙酯部分对瓜果腐霉和棉花枯萎病菌的生长也有较强的抑制作用,在1mg/mL时抑制率分别为45.8%和23.9%。研究结果表明,皂英抗菌活性成分主要存在于棘刺中的乙酸乙酯极性段和正丁醇极性段中。

Inhibitory effects of Gleditsia sinensis extracts on some plant pathogens

Gleditsia sinensis, one of leguminous species, is a traditional Chinese medicinal plant. It only distributes in China with great resource in many parts of the country. Inhibitory effects of the leaf and spina extracts and fractions against Bacillus subtilis, Erwinia carotovora var. carotovora, Xanthomonas vesicatoria, Botrytis cinerea, Cladosporium fulvum, Fusarium oxysporum f. sp. vasinfectum and Pythium aphanidermatum were tested in vitro. Leaf ethanol extract did not show any antimicrobial activities at the tested concentration. But spina ethanol extract showed antibacterial activity against B. subtilis and X. vesicatoria with minimal inhibitory concentrations ( MIC) of 2. 5 mg/mL and 10 mg/mL respectively. The growth of all four phytopathogenic fungi was inhibited by spina ethanol extract at concentration of 1 mg/mL. Inhibitory rate of the extract on P. aphanidermatum was 28. 4%. Petroleum ether, chloroform, ethyl acetate, n-butanol and aqueous fractions obtained from spina ethanol extract were further tested for their antimicrobial activities. Ethyl acetate fraction showed the strongest inhibitory effects on B. subtilis, X. vesicatoria and E. carotovora var. carotovora in comparison with other fractions. MIC of ethyl acetate fraction on B. subtilis and X. vesicatoria were 1.25 mg/mL and 5 mg/mL respectively. Among the five fractions, ethyl acetate fraction also showed the strongest inhibitory effects on P. aphanidermatum and F. oxysporum f. sp. vasinfectum with inhibitory rates of 45.8% and 23.9% respectively, when tested at concentration of 1 mg/mL. The results indicated that the antimicrobial compounds might exist mainly in ethyl acetate and n-butanol fractions of G. sinensis spina.