Broad Spectrum Of Biological Pesticides Trichoderma Mutagenesis And Antagonistic And Biocontrol Role

Trichoderma spp. are fungi that are highly interactive in root, soil and foliar environments. They are frequently dominant components of the microflora in widely varying habitats. They can biocontrol against a wide range of plant-pathogen. Furthermore, they are potent producers of a variety of plant polysaccharide degrading enzymes and capable of degrading a variety of xenobiotic materials. Trichoderma frequently enhances plant growth, the uptake and use of these nutrients.Out of 255 isolates of Trichoderma from 852 soil samples in Shandong Province, eight Trichoderma species were identified by conidiophore morphology and cluster analysis for soluble protein. With optical microscope and polyacrylamide gel eletrophoresis, they are Trichoderma harzianum, Trichoderma citrinoviride, Trichoderma longibrachiatum, Trichoderma viride, Trichoderma hametum, Trichoderma aureoviride, Trichoderma konningii and Trichoderma pseudokong.T32 was efficient for controlling some soil-borne plant-pathogenic fungi than others. The main mechanisms are as follows: mycoparasition, competition for nutrients and space. In dual cultures with 6 soil-borne plant-pathogenic fungi, T32 hyphae attached to the host Rhizoctonia solani and coiling around the pathogen hyphae and parasitied into pathogenic hyphae. The phenomenon of competition for nutrients was illustrated in dual cultures with Verticillium dabliae, Fusarium var vasinfectum, Ustilago maydic. T32 competed space against Fusarium bulbigenum, Fusarium solani in dual cultures.Mutations were conducted under certain condition, UV light and ⁶⁰Co-γ rays. T32 was treated with an appropriate ⁶⁰Co- γ radiation dose (0.8 kGy-1 kGy) and UV radiation time was 5-7 minites. Mutants tolerant of chemical fungicides were selected. The stable mutants T1010 with high production of spores and high growth rate were selected against soil-borne plant-pathogenic fungi in dual cultures in comparison with...