Abstract: This work aimed to explore the diversity of Trichoderma from the rhizosphere soil of vegetables under facility culture as well as their aniti-phytopathogenic fungi and organophosphorus-degrading activity. Trichoderma were isolated from the rhizosphere soil and the roots of the sampled tomato from facility culture fields for more than 20 years of cultivation,and were identified by tef1-α sequencing combined with phylogenetic analysis. Besides,the relative population density of each strain was estimated,and the biocontrol activity and the degradation activity were further studied. Results showed that 27 different strains were isolated,and then identified based on the morphological characteristics and tef1-α,they belonged to T. virens,T. atrobrunneum,T. simmonsii,T. atroviride,T. crassum and one suspected new species T. sp. nov. Conidiation of Trichoderma strains usually was distributed unevenly,more or less concentric,and bright green to dull green. All the strains showed varied levels of inhibiting activity to several plant pathogenic fungi such as Rhizoctoma solani,Fusarium oxysporum and Verticillium dahlia. In the degradation experiment of chlorpyrifos,except strains belonging to T. atrobrunneum,strains in other Trichoderma species effectively degraded chlorpyrifos. The relative population density of Trichoderma in the rhizosphere soil was 104 cfu/g,and there was significant difference among different strains. The results indicate that there is rich Trichoderma germplasm diversity in the soil under facility culture,and they show obvious strain difference in morphological characteristics and functional activities. Trichoderma strains have general inhibiting activity to three plant pathogenic fungi,and some of them can effectively degrade organophosphorus pesticide. Thus,they play a synergistic effect of biocontrol and biodegradation of pesticides and fertilizers. The results of this paper are of great significance for the study of the adaptability of Trichodema in the soil of facility agriculture and the exploitation and utilization of Trichoderma resources.

Key words: facility agriculture, Trichoderma, phylogenetic analysis, biocontrol activity, bioremediation