Screeing Of Antagonistic Trichoderma Strains To Carbendazim And Study Of Its Characteristic

Trichoderma spp. are promising biocontrol agents(BCAs) of plant diseases. There is no systematic report about the sensitivity of Trichoderma for commonly used bactericidal agents at pesent.So it lies impotant sense to induce Trichoderma to produce multiplical resistance.This article dicusses the screening and determination of its characteristic for biocontrol Trichoderma strains tolerant to carbendazim.With PDA medium containing fungicides and ultraviolet radiation, Trichoderma are obtained carbendazim stress from initial antagonistic strain.Five Trichoderma strains are screened.The carbendazim tolerance rises at most 450 times than parent strain.The resistance is not decline after transfering ten times continuously.T42-2 is determined as the best strain because of bearing high carbendazim stress,growing fast and biocontroling well.Its biocontrol effect is 88.93% against Botrytis in vivo,as a result which can prevent cucumber gray mold efficiently. There is close relation spore germination among temperature, pH and medium.Illumination has no significant promotion.Trichoderma T42-2 can survive at 10～35℃,and grows best at 28℃.Acid condition is more suitable for T42-2, pH 5～6 is the most acidity. Trichoderma needs nutrition promoting sprout, opitimist nitrogen source is peptone, carcon source is lactose.Spores don't germinate in distilled water.T42-2 has evident inhibitory action to three pathogenic bacterium,including Botrytis cinerea,which includes multiple mechanism and is various as the kind of pathogenic bacterium. Nourishment competition and superparasitism are the principal mechanism,but there is no antibiotics.In toxicity experiment,Ec50 of T42-2 to carbendazim, sumilex, thiophanate-methyl,dacodan and tradimefon rise greatly,iprodione and catch Botrytis decline.