Isolation,Identification And Biocontrol Function Of Three Trichoderma Strains

Trichoderma spp. are a kind of filamentous fungi, which are widely distributed and have strong ability to adapt different environments. Trichoderma spp. are used as one of the most important strains in biological control of plant disease and they get more and more attention of researchers. According to the importance of the Trichoderma strains, we explored the biocontrol ability on rape sclerotinia rot blight and tomato gray mold. Results are as followed:1. From the corn in the field of Anyang City, Henan Province, we isolated three Trichoderma spp. strains by plate dilution coating method, named 1-2-1, 1-3-2, 5-2-2. According to the colony characteristics, morphology characteristics and phylogenesis analysis of tef1-α, strain 1-2-1 and 1-3-2 were identified as Trichoderma afroharzianum, strain 5-2-2 was identified as Trichoderma asperellum.2. The biological characteristics of the three strains are tested, including the growth rate and spore yield under different temperature and pH. The results showed that the optimum growth temperature of the three strains is 30℃, the optimum sporulation temperature is 25-30℃, the optimum pH is 3-6.3. Researching the ability of three strains antagonistic two plant pathogen Sclerotinia sclerotiorum and Botrytis cinerea. We co-cultured the pathogen and three Trichoderma strains respectively in plate, the results showed that the two pathogens were significantly inhibited. The growth rate of the pathogen was slowed and the sclerotia formation was inhibited. Under the optical microscope, we can find that the Trichoderma hyphae winding the pathogen hyphae. The three Trichoderma strains, including 1-2-1, 1-3-2 and 5-2-2, had very strong parasitic effect on sclerotia of S. sclerotiorum, the rot index were 73.3, 66.2 and 91.7.4. To test the control effect of the two pathogen strains, we used 108 /ml spore suspension to spray on plant leaf before inoculum test measured on sclerotinia rot blight and gray mold. The experimental results showed that: there were liter or no obvirous disease spot appeared on the the tomato leaves treated with conidia suspension; but the spore suspension in vitro inoculation of rape sclerotinia rot blight had no obvious effect.