苦参提取物对茄子黄萎病菌的化感效应研究初报

Preliminary Studies about Allelopathic Effect of Sophora flavesecns Extracts on Verticillium dahliae of Eggplant

提取苦参主要活性成分黄酮类化合物和生物碱,分别测定其抑菌活性;并通过苦参提取物对茄子黄萎病菌菌丝干质量、菌丝毒素含量与胞外酶活性的影响来分析其化感抑制作用机理。结果表明:经过抑菌活性测定,对茄子黄萎病菌具有化感抑制作用的苦参活性成分主要是黄酮类化合物。在苦参黄酮类化合物浓度为4.00 mg.mL-1培养7 d时抑菌率达100.00%,培养9 d时抑菌率为98.28%,与其他处理差异均达显著水平;培养12 d时,苦参黄酮类化合物浓度大于1.00 mg.mL-1的抑菌率还维持在90%左右。苦参生物碱处理的抑菌率均低于同浓度的黄酮类化合物处理的抑菌率。经过苦参提取物处理后,茄子黄萎病菌菌丝干质量随着提取物浓度的增加呈下降的趋势,菌丝毒素含量也随之下降,同时胞外酶活性降低。在苦参提取物浓度大于10 mg.mL-1时,抑制作用均与对照差异达显著水平。苦参提取物通过降低茄子黄萎病菌胞外酶活性、菌丝毒素含量,从而达到对菌丝生长的化感抑制作用,主要表现为菌丝干质量的降低。

The main active substance extracted from Sophora flavesecns is flavonoids and alkaloids,determine the inhibitory,study the effect of extracts on mycelium dry weight,toxin contents and the activities of extracelluar enzymes,analyze allelopathic inhibition mechanism.Extracts of S.flavescens showed inhibitory effects on Verticillium dahliae allelopathicly owning to its active substances flavonoids and alkaloids.The inhibitory rate is 100.00% 7 days and 98.28% 9 days after treatment with concentration 4.00 mg·mL-1 flavonoids,the inhibitory rate remained about 90% on the 12th day with the concentration 1.00 mg·mL-1 flavonoids.Lower inhibitory rate was found when treated with the same concentration of alkaloids.The mycelium dry weight,toxin contents and the activities of extracellular enzymes decreased with the increase of S.flavescens extracts concentration.The inhibitory effects were significant compared to the CK with the extract concentration over 10 mg·mL-1.By reducing the activities of extracellular enzymes and the toxin content,the growth of mycelium was inhibited,mainly expressed as the reduced dry weight of mycelium.