Studies On The Antagonistic Mechanism, Promotion And Preparation Of Trichoderma Aureoviride

The antagonistic mechanism of Trichoderma aureoviride to the pathogen causing Lily blights (Phytophthora nicotianae van Brede de Haan), promotion of growth to various plants and the preparation of T. aureoviride were studied in this paper.The results showed that the biocontrol mechanism of T. aureoviride restraining P. nicotianae was mycoparasitism and competition of nutrition,and antibiotic substances were detected by a series of investigation means,such as confronting each other,degrading hypha,mensurating antibiosis substances,cultivating face to face, cultivating in sieve film of disc, mensurating activities of enzyme.The ratio of growth speed was 3.68 in confronting each other after 60h,and the activities of chitinase andβ-1,3-glucanase were detected in the ferment filtrate. In addition, the pathogenic hyphae could be degraded by T. aureoviride filtrate, which showed existence of parasitism.The medium and culture conditions were tested in experiment.In second-grade liquid culture, the optimum medium was wheat bran decoction.The optimum conditions were the inoculum 1.0%, continuous light, 25℃,pH5.0, and rotate speed 150r/min.The harvest period was five days.The conidial concentration reached 1.91×1010 spores/ml. In third-grade solid culture in plate, the optimum medium was wheat bran-clay(1:1).The optimum conditions were the proportion between water and medium 1:0.8, the inoculum 30%, the variational temperature(prophase 20℃,metaphase 24℃a nd anaphase 28℃),the thickness of medium 1.0cm and agitating medium every 12h. The fermentation period was ten days.The conidial concentration reached 3.41×1010spores/g.To T. aureoviride preparation ,the optimum temperature and time of desiccation were 30～35℃,48h respectively.Under these conditions the rate of alive spore reached 90%.And the preparation was packed with kraft at 4℃.The rate of bud was 32.8% after six months.The bud and growth of wheat, alfalfa and cucumber was promoted by T. aureoviride preparation. In soaking seed experiment, the growth of wheat and alfalfa was promoted by 200X preparation,especially wheat (index of bud and energy were 11.8 and 0.437).But high concentration(10X,20X,50X) restrained the growth of plants.In soil experiment, it was helpful to soak seed to germination of wheat(500X) and alfalfa...