Characterization of secondary metabolites and enzymes produced by Trichoderma species and their efficacy against plant pathogenic fungi

Abstract

The secondary metabolites from culture filtrate and mycelial mass of potential isolates of Trichoderma viride (IARI P1 and IARI P2), T. virens (IARI P3) and T. harzianum (IARI P4) were extracted by solvent extraction and soxhlet water bath distillation methods and evaluated at different concentrations against Rhizoctonia bataticola (dry root rot of chickpea) and Fusarium oxysporum f. sp. ciceris (wilt of chickpea). All concentrations (500, 250, 125 and 75 ppm) were found to be inhibitory to these pathogens. Higher concentrations were found to be inhibitorier than the lower ones. 47.8% to 78.0% inhibition of mycelial growth was recorded even at 75ppm concentration. Some of the compounds, namely, 6-nonylene alcohol, massoilactone, methyl-cyclopentane, methyl cyclohexane, N-methyl pyrollidine, dermadin, ketotriol, koningin-A, 3-methyl-heptadecanol, 2-methyl heptadecanol, palmitic acid, 3-(2’-hydroxypropyl)-4-(hexa- 2’-4-dineyl)-2-(5H)-furanone and 3-(propenone)-4-(hexa-2’-4’-dineyl)-2-(5H)-furanone from these metabolites were chemically characterized by GC-MS/MS. Growing culture in shaker incubator at 25°C and 6.5 pH was found to be the optimum conditions for production of maximum proteins. The activities of defense-related enzymes, namely, chitinase and ß-1, 3-glucanase produced by the above mentioned Trichoderma species were determined. All Trichoderma species showed the activity of these enzymes. Moreover, chitinase activity was maximum in T. virens, whereas, ß-1, 3- glucanase activity was maximum in T. viride among the tested cultures