Cellulase and chitinase activities and antagonism against Fusarium oxysporum f.sp. cubense race 1 of six Trichoderma strains isolated from Mexican maize cropping.

Abstract

To evaluate the enzymatic and biocontrol capacity of native Trichoderma strains isolated from corn crops in Irapuato (state of Guanajuato) and Napízaro (state of Michoacán), Mexico. Six native strains from Irapuato and Napízaro were tested, with five of them identified as T. harzianum and one as T. tomentosum. The six strains qualitatively and quantitatively showed enzyme activity for cellulase and chitinase. The best results were obtained for strains IrV6SIC7 and MichV6S2C2 with 878IU L-1 of chitinase and 1323IU L-1 of cellulase, respectively. All Trichoderma strains acted antagonistically toward Fusarium oxysporum f.sp. cubense race 1 (FocR1), with percentages of inhibition that ranged from 9 to 54%. In addition, the microscopic analysis allowed visualizing the mechanisms of mycoparasitism and antibiosis by either IrV6SIC7 or MichV6S2C2. The latter effects indicate that the tested native Trichoderma strains isolated from corn crops possessed enzymatic mechanisms as a strategy for biocontrolling FocR1 strains. The enzyme production by the Trichoderma strains represents a potential biotechnological utilization for either agricultural or industrial purposes.