Study On Biocontrol And Mechanism Of Trichoderma Spp.-spent Mushroom Substrate Fermentation To Cucumber Soil-borne

With the development of the mushroom industry,the spent mushroom substrate caused serious environmental pollution and the enormous waste of resources.Therefore,the disappearance of the re-use study closely watched.In addition,the soil-brone has risen for the main vegetable disease in the vegetable cultivation.This paper study the fermentation of anti-Trichoderma on the spent mushroom substrate,the application of the spent mushroom substrate on the control of the soil-borne and the mechanism.1.Initially clear the type of Trichoderma spp.on the contaminated mushroom substrate. Trichoderma.spp samples of the substitute cultivation of edible fungi were collected from suburb of Beijing. We aggregately isolate 296 Trichoderma spp..Identified by Morphological observe,there are Trichoderma viride,Trichoderma koningii,Trichoderma pseudokoningii,Trichoderma harzianum,Trichoderma hamatum,Trichoderma longibrachiatum,Trichoderma aurecviride and Trichoderma citrinoviride,eight species.The isolated frequency of Trichoderma viride is 48.31%.2.Select a fine strain-Trichoderma viride TH4 from the isolated.Through confront culture and pot experiment,we find Trichoderma viride TH4,which has strongly antagonized with two soil-borne pathogens.The control effect to the Fusarium oxyporum and Rhizoctonia solani are 78.59%and 86.17%in pot experiment.3.Determine the fermentation conditions of TH4 on the spent mushroom substrate.When the temperature is about 25℃,the substrate:H₂O is 1:2,initial pH is about 6.0,Trichoderma TH4 ferments 6～7 days on the substitute cultivation of mushroom,this circumstance will benefit to the TH4 germination. Owing to the absence of nitrogen in spent mushroom substrat,the supplement nitrogen(NH₄NO₃ and NaNO₃)will enhance the number of spores.In addition,Ca²⁺,Mg²⁺,K⁺,Fe²⁺may influence the producing spore time.4.Through the pot experiment,we see the TH4-spent mushroom substrate fermentation product and the proportion of cultivated soil 1:20,for seven days the plant can withstand pathogens and promote growth.5.Antagonistic mechanism of TH4 to Fusarium oxyporum was studied in this research.TH4 and Fusarium oxysporum is dual culture on PDA,found out that TH4 has the absolute advantage of mycelium growth.The junction of two strains of mycelium is scratched.From the microscopic observation,we found Trichoderma TH4 mycelium can he entangled,penetrate Fusarium oxysporum mycelium,parasite on the cell wall,and finally to demise.By the cellophane disk method and enclosed chamber test,we drew the conclusion that the non-volatile metabolites and volatile metabolites of TH4 had the inhibition effect to Fusarium oxysporum,the inhibition rate was 19.29%and 33.54%.6.TH4-spent mushroom substrate fermentation product added to the cultivated soil,the photosynthesis rate is improved,the cucumber chlorophyll content is increased,the growth of cucumber is higher,and promote the growth of cucumber.7.TH4-spent mushroom substrate fermentation product added to soil cultivation,Trichoderma spp. colonized in the rhizospbere of the cucumber.In the induction of pathogen,chitinase andβ-1,3 - glucanase activity has greatly improved,and the effect of pathogen has enhanced.8.TH4-spent mushroom substrate fermentation product induce systemic resistance to cucumber other leaf pathogen.When cucumber grew the second leavest,we extract peroxidase such as CAT from the cucumber leaf and soluble protein.The enzyme activity determined that TH4-spent mushroom substrate fermentation product can promote peroxidase activity.Thereby increasing the resistance of cucumber seedlings.In addition,the promotion of soluble protein increases the metabolism of cucumber.The study fist propose that we can regard the spent mushroom substrate fermentation product as a new type of soil additives used in cucumber cultivation facilities,in order to prevent cucumber soil-borne diseases.And we make clear of the application of this soil additives.