香芹酚与百里香酚及其衍生物对杜仲灰斑病致病菌的生物活性研究OA

[Objective]The biological activity of carvacrol,thymol and their derivatives against Alternaria tenuis causing gray spot disease of Eucommia ulmoides was investigated to clarify their antibacterial mechanisms against the pathogen,and provide a theoretical basis for development of green and efficient fungicides based on monoterpene phenols and their derivatives to effectively prevent and control gray spot disease of E.ulmoides.[Method]The effects of 4 compounds including carvacrol,thymol,acetylated carvacrol and acetylated thymol with 5 different concentrations on mycelial growth rate,mycelial integrity and cell membrane permeability of gray spot disease of E.ulmoides were determined by taking A.tenuis suspension and chlorothalonil as the blank control and positive control respectively.[Result]Carvacrol,thymol,acetylated carvacrol and acetylated thymol all had inhibitory activity against A.tenuis causing gray spot disease of E.ulmoides,and the inhibitory rate was on the rise with increase of fungicide concentration.The inhibitory rate of 130 mg/L carvacrol,300 mg/L thymol,130 mg/L acetylated carvacrol and 300 mg/L acetylated thymol against A.tenuis was 90.09%,86.38%,85.14%and 85.38%and their EC50 values after 6 d culture ranged from 48.662 to 164.080 mg/L.The mycelial morphology of A.tenuis treated with carvacrol and thymol showed distortion and fracture status,but the mycelial morphology of A.tenuis treated with acetylated carvacrol and acetylated thymol under 5 different concentrations was not changed obviously.Carvacrol,thymol,acetylated carvacrol and acetylated thymol treatment increased K+content and cell membrane permeability of mycelial,which insulted in release of intracellular substances in mycelial and the cell membrane permeability of mycelial decreased with extension of treatment time.Chlorothalonil had a little effect on increase of cell membrane permeability.[Conclusion]Carvacrol,thymol and their acetylated derivatives all have the inhibitory activity against A.tenuis,causing gray spot disease of E.ulmoides and are better than chlorothalonil in safety of green and environmental protection,which indicates that these compounds have a better development potential.