QUALITATIVE AND QUANTITATIVE ENZYMATIC PROFILE OF NATIVE Trichoderma STRAINS AND BIOCONTROL POTENTIAL AGAINST Fusarium oxysporum f.sp. cubense RACE 1

Abstract

Trichoderma is a ubiquitous fungal genus in the rhizosphere, often utilized as biofertilizer and biocontrol agent that may release enzymes involved in the control of certain fungal phytopathogens. This research evaluated the biotechnological potential of fifteen native Trichoderma strains that were previously isolated from the rhizosphere of maize cultivated at the Estado de Mexico (Mexico). The radial growth rate of each fungal strain was assessed as well as the qualitative analysis of enzyme activity on specific culture media. Then, eight prominent strains were selected for evaluating their capability of degrading four complex substrates (filter paper, newspaper, starch, and chitin), and their antagonism towards five isolates of Fusarium oxysporum f.sp. cubense Race 1 (FocR1). Eight out of the fifteen Trichoderma strains showed high radial growth rate (0.137-0.149 cm/h), and good qualitative enzyme activities (cellulase, pectinase, and chitinase) when compared to a positive control strain T. reesei CDBB-H-356. The best eight strains (EMV6SIC2, EMV6SIC4, EMV6SIC5, EMV6SIC6, EMV6SIC7, EMV6SIC8, EMMVrSIC4, and EMMVSIC2) showed good inhibition to the five FocR1 isolates (ranging from 3 to 54%), and good capability for degrading cellulosic substrates (filter paper and newspaper) via production of active enzymes. Data were analyzed by one way analysis of variance (ANOVA), followed by a multiple comparison test (Tukey, α=0.05). In conclusion, some native Trichoderma strains have good biotechnological potential for being directed to the industry since they produce cellulases; at the same time, these fungal strains may release chitinases by which fungi may control and degrade the cell wall of FocR1 isolates.