و مقايسه با عوامل فوزاريوز سنبله گندم و فعاليت آنتاگونيستي آن بر عليه اين بيمارگرها TRICHODERMA KONINGI و دما روي رشد PH بررسي تاثير

Effects of pH and temperature on growth rate of Trichoderma koningii and comparison with Fusarium spp. causal agent of wheat head-blight and its antagonistic activity against the pathogens

In this study the effects of pH and temperature on antagonistic activity of the fungus Trichoderma koningii (KR7) from Gorgan area (Agh-ghaleh) were compared with two species of Fusarium causal agents of wheat head-blight disease. This T.koningii had significantly the most growth rate at 25ʹC and pH4.5. The growth rate was more in all tested temperatures (20, 25 and 30ʹC) with pH 4.5, than two others pH 5.5 and 6.5. Reduction of pH resulted in an increase in the sporulation of T.koningii, but, Fusarium graminearum and F. culmorum were associated with growth reduction more at 30ʹC. Optimum growth for two species of Fusarium was 25ʹC. After 48h F.culmorum produced high level of macroconidia on PDA whereas, none with F.graminearum. Growth rate of T koningii was significantly more than two Fusarium species in dual cultures. Phenomena of mycoparasitism and colonisation of T.koningii on Fusarium hyphae was associated with coiling around hyphae in various experimental conditions, observed by light microscope. T.koningii fungus produced green conidia and chlamydospore after 48h, in dual and single culture.