Chitinase and beta-1,3-glucanase activities of Trichoderma harzianum in response towards pathogenic and non-pathogenic isolates: early indications of compatibility in consortium

The expression of chitinase and Beta-1,3-glucanase activities of Trichoderma harzianum in response towards pathogenic (Fusarium oxysporum f.sp. cubense race 4, Ganoderma boninense) and non-pathogenic isolates (T. viridescens, Serratia marcescens, Streptomyces griseus) were investigated. Results revealed that T. harzianum produced both enzymes naturally (in the absence of pathogens and non-pathogens). T. harzianum did not discriminate between pathogenic and non-pathogenic isolates as similar levels of chitinase and Beta-1,3-glucanase were produced. Among the five isolates tested, S. marcescens proved to be the most suitable and compatible isolate with T. harzianum, with high enzymatic levels detected in co-inoculations. On the contrary, T. viridescens was the least beneficial, eliciting the least enzymatic activities from T. harzianum. This was presumably a demonstration of the kin selection hypothesis, which allows co-existence of both Trichoderma isolates in consortium. The interactions of T. harzianum with all tested isolates offered preliminary insights into the effectiveness of Trichoderma-based consortia, particularly via chitinase and Beta-1, 3-glucanase activities. We recommend further investigations on the use of S. marcescens with T. harzianum due to their compatibility and high levels of enzymatic activities.