Investigating the interaction of some mutated strains of Trichoderma species and Piriformospora indica on Cucumber wilt caused by Fusarium in greenhouse

The aim of this study is to investigate the interaction effects of two Trichoderma spices (T.koningii and T. virens) mutants and endophyte Piriformospora indica on infected cucumber plants by Fusarium oxysporum f. sp. radicis-cucumerinum (Forc) and evaluating their mutual influence on growth indexes in cucumber plants.The efficient wild-type Trichoderma isolates were selected by dual-culture test (T.koningii NAS-108 with 50% and T.virens NAS-115 with 33% inhibition of pathogenic growth) and their spore suspension with a concentration of 106 (spore/ml) in a dose range of 250 Gy was irradiated with gamma rays. NARS-TKM101 and NARS-TviM112 mutants showed highest antagonistic activity by 20% and 100% increase compared to their wild-type strains and they with their wild-type strains, were used for greenhouse evaluations. The combined treatments of Trichoderama sp. (total wild types and total mutants) with P. indica showed the most positive effects on seedlings growth indices length and dry weight (stem and root). No significant difference was observed between un-irradiated and mutant strains of Trichoderma in reducing disease index, (p<5%), but the combined treatments of two Trichoderma fungi (total mixed Trichoderama wild types and total mutants) with P. indica led to significant reduction of disease index (p<5%) and were more successful than the carbendazim fungicide in the plants infected with Forc.