大蒜秸秆水浸液的抑菌作用和抑菌成分初步分析

Primary Study on the Inhibitory Effects on Plant Pathogen and the Inhibitory Ingredient of Garlic Straw Aqueous Extracts

以不同浓度的大蒜秸秆水浸液对西瓜枯萎病菌、黄瓜枯萎病菌、辣椒疫霉病菌进行抑菌圈试验,并对3种不同的大蒜秸秆萃取液中的可挥发抑菌物质进行鉴定,以了解大蒜秸秆水浸液的抑菌作用。结果表明,大蒜秸秆水浸液对3种靶标菌均有抑菌活性,其最有效的抑菌浓度为100 g.L-1,对辣椒疫霉病菌的抑菌活性最强。大蒜秸秆水浸液的石油醚、三氯甲烷和乙酸乙酯3种有机溶剂萃取相对3种靶标菌均有抑菌活性,以乙酸乙酯相抑菌活性最强,在50 g.L-1浓度下对辣椒疫霉菌抑菌率达100%,在100 g.L-1浓度下对西瓜枯萎病菌和黄瓜枯萎病菌的抑菌率也达100%;三氯甲烷相的抑菌活性稍高于石油醚相;抑菌活性基本随浓度增加而增大。经GC-MS分析,初步确定大蒜秸秆水浸液中的可挥发抑菌物质主要有2-甲氧基-1,6-己二酸甲酯、邻苯二甲酸二丁酯等有机酯类,3-甲氧基-4-羟基-苯甲酸、对羟基苯甲酸等有机酸,以及对甲氧基苯酚等酚类化合物。

The suppression circle of different concentration garlic straw aqueous extracts to Fusarium oxysporum（Schl.） f.sp.niveum（E.F.Smith） Snyderet Hansen,Fusarium oxysporum（Schl.）f.sp.cucumerinum Owen and Phytophthora capsici Leonian was measured to investigate the inhibitory effects of garlic straw aqueous extracts on plant pathogen,and the volatile inhibitory ingredients in three kind of garlic straw aqueous extracts were identified.The results showed that garlic straw aqueous extracts had inhibitory effects on all the three pathogens,the most effective concentration was 100 g·L^-1,and the most effective target pathogen was P.capsici.All the three organic fractions of the aqueous extracts showed inhibitory effect on the pathogens.Among them,the ethyl acetate fraction showed the highest inhibitory effects on all the pathogens,and the inhibitory rate reached 100% to P.capsici at the concentration of 50 g·L^-1.The inhibitory rate also reached 100% to F.oxysporum f.sp.cucumerinum and F.oxysporum f.sp.niveum Hansen when the concentration of the ethyl acetate fraction increased to 100 g·L^-1.The chloroform fraction showed higher inhibitory effects than petroleum ether fraction,and both of their inhibitory effects showed increasing trend with the increase of their concentration.By means of GC-MS analysis,the major volatile inhibitory ingredients in garlic straw aqueous extracts were preliminarily determined to be the ester like compounds such as dimethyl 2-methoxyhexane-1,6-dioate and dibutyl phthalate,the organic acid like compounds such as 4-hydroxy-3-methoxy benzoic acid and 4-hydroxy-benzoic acid,and the phenol like compounds such as mequinol.