论文部分内容阅读
In this study, 36 soil samples were collected from tobacco filed in Songxian, Luoning and Ruyang counties of Luoyang.Through isolation and purification, 27 isolates of Trichoderma were obtained.7 isolates of them had been acquired via the method of confrontation test on PDA to 3 important tobacco root pathogens, Phytophthora parasitica var.nicotianae Tucker, Pythium aphanidermatum Fitzpatrick and Fusarium oxysporum.The inhibition rate range from 70.31% ~89.58%.The biggest inhibition is 7.6mm.Through the identification based on morphology and analysis of rDNA-ITS sequencing,these 7 isolates were identified as 4 species including Trichoderma harzianum, T.aureoviride,T.tomentosum and T.velutinum.Trichoderma harzianum and T.aureoviride are super biocontrol Trichoderma species from tobacco soil in Luoyang, and these Trichoderma species all had the best inhibition against those 3 tobacco root pathogens in this study.