Measuring of -1,3 Glucanase Activity in Trichoderma Virens Isolates and Selection of the Best Isolates for Biological Control of Cucumber Root Rot

In this study four isolates of Trichoderma virens (T.virens 414, T.virens 414.8, T.virens 304 and T.virens 404.4) were compared based on extra cellular β-1,3 glucanase production and biological control of root rot cucumber (Phytophthora drerchsleri) in laboratory and green house experiments.The in vitro potential of those isolates were evaluated against P.drechsleri through production of volatile and dual culture. The pH (3, 5, 7, 8, 9) and temperature effects(5, 15, 20, 25, 30, 40˚C) on Trichoderma mycelial growth were also evaluated. Colony growth rate of thease isolates were also studied in water agar culture medium containing carboxy methyle cellulose (CMC) and showed direct correlation with β-1,3 glucanase secretion. According to results T. virens 304 and T. virens 414.8 were the best isolates in biocontrol of. drechsleri. Result also showed direct correlation between β-1,3 glucanase secretion and inhibition growth of phytophthora mycelium and reduction of phytophthora infection.