核桃青皮乙醇提取物对三种猕猴桃软腐病菌的抑制作用

Inhibitory Effects of Walnut Green Husk Ethanol Extract on Three Pathogenic Fungi Causing Fruit Rot of Kiwifruit

为探究核桃青皮提取物对猕猴桃软腐病的防治作用,本研究采用生长速率法研究了不同浓度核桃青皮乙醇提取物(0,1.25,2.5,5,10,20 mg/mL)对3种猕猴桃软腐病致病菌[间座壳菌(Diaporthe sp.),拟茎点霉菌(Phomopsis sp.)以及细极链格孢菌(Alternaria tenuissima)]的抑制效应。结果表明,核桃青皮乙醇提取物对这3种供试病原菌均有明显的抑制作用,且乙醇提取物的浓度越高,抑制效果表现越明显。当乙醇提取物浓度达到20 mg/mL时,对间座壳菌、拟茎点霉菌和细极链格孢菌的抑制率分别为85%、88%和66%;其EC50值分别为17.79、19.20和12.94 mg/mL。这些结果表明核桃青皮乙醇提取物对间座壳菌和拟茎点霉菌的抑制效果比细极链格孢菌明显,且与室内防治效果一致。本研究为核桃青皮提取物防治猕猴桃软腐病提供参考。

The inhibitory effects of walnut green husk extracts on Diaporthe sp.,Phomopsis sp.and Alternaria tenuissima,which can cause to fruit rot of kiwifruit were estimated in this study.The virulence of its ethanol extracts at the different concentrations(0,1.25,2.5,5,10,20 mg/mL)against these pathogens were estimated using mycelium growth rate method.The results indicated that ethanol extract of walnut green husk can significantly inhibit the mycelium growth of three tested pathogens and exhibited the different inhibitory effects on the same pathogen at the different concentrations.When the concentration of ethanol extract reached to 20 mg/mL,the mycelium growth inhibition rate of Diaporthe sp.,Phomopsis sp.and Alternaria tenuissima were 85%,88%and 66%with EC50 values 17.79,19.20 and 12.94 mg/mL,respectively.In addition,the results suggested that ethanol extract of walnut green husk had the better inhibitory effects on Diaporthe sp.,Phomopsis sp.than Alternaria tenuissima,which was consistent with their indoor control efficacy.This study provides the evidence of ethanol extract of walnut green husk to control fruit rot of kiwifruit.