Screening And Optimization Of Culture Conditions For Antagonistic Strain Against Alternaria Alternate Of Cucumber

Using of a particular mass medium for the separation and purification, getting the eight strains of Trichoderma strains. respectively, T-1, T-2, T-3, T-4, T-5, T-6, T-7 , T-8. The beginning of strain colony is white, dense, round, extended to four weeks after the central produce green spores from the colony, the central green. White fungal colonies grow around the band, and finally all the colonies become greenTrichoderma strains by these eight growth rate determination, screening three rapid growth of selected strains are T-1, T-5 and T-7. Rescreening confrontation with the black spot disease of cucumber experiment to find good antagonistic strains. Strain T-7 which is the best antagonistic strains, and its performance for the Trichoderma antagonistic contact with the spots will be covered on the surface dark spots and parasitic growth, so that spots can not continue to grow, or even death.By antagonistic Trichoderma strains screened T-7 for the optimization of culture conditions, we found that ph value, temperature and nutrition has a distinct role on the growth of antagonistic strains, and light conditions, training time and other factors is not significant. We found that the optimal orthogonal experimental culture conditions: pH 6, temperature 28.5℃, carbon source is 15g / L of lactose dosage .To improve the antagonistic strains of black spot disease control effect on cucumber, using a mutagenesis approach to enhance the antagonistic ability of Trichoderma strains antagonistic. Experiments using ultraviolet irradiation on strain T-7 were mutagenic treatment, repeated after 2 mutation screening, and ultimately be more effective against black spot disease of cucumber antagonistic strainsⅡ-8, in the confrontation experiment, the average strains growth speed of 0.798mm/h, an increase of previous strains 0.061mm/h. Mutagenesis initial results. Seedlings with Trichoderma fermentation and soil treatment was found to promote the growth of cucumber, fresh weight increased to 22.60% and 36.96%. To the growth position, fluid in the Trichoderma spores soaked seed is better than not soaked seed, the shoot and root length increased by 67.59%, respectively, and 33.07%. Pot experiments, we found that liquid water with Trichoderma spores of cucumber cucumber seeds can eliminate or reduce the adverse effects of black spot pathogen, when Trichoderma spore concentration was 1×10~8/mL, the disease index of only about 30%, control effect Can achieve 61.29%.