Effect of Benomyl on Chitinase and -1,3-Glucanase Production by Free and Alginate Encapsulated Trichoderma harzianum
Mohammed S. El-Katatny, Hesham M. El-Komy*, Gehan M. Shaban, Ahmed M. A. Hetta and Momein H. El-Katatny
Department of Botany, Faculty of Science, El-Minia University, El-Minia, 61519, Egypt
Article history:
Received December 12, 2003
Accepted April 15, 2004
Key words:
Trichoderma spp., biocontrol, chitinase, glucanase, benomyl, fungicides, immobilisation, Ca-alginate
Summary:
On PDA-benomyl plates growth of Trichoderma harzianum was inhibited by 20 and 30 % at benomyl 1 and 2 g/mL, respectively, and was completely inhibited at 5 g/mL. In minimal synthetic medium (MSM) amended with different concentrations of benomyl (1.0, 3.0, 5.0, 7.0 and 10.0 g/mL), fungal immobilisation improved chitinase and -1,3-glucanase production at low benomyl concentrations (1, 3 and 5 g/mL). Further increase in the production of both enzymes was obtained by immobilisation at higher benomyl concentrations (7 and 10 g/mL). Fungal immobilisation increased bound chitinase by 15- to 30-fold at 3 and 5 g/mL benomyl concentration, respectively. However, no effect was obtained on the bound -1,3-glucanase. Different benomyl concentrations (0.3 to 1500 g/mL) had no significant inhibitory effect on the activities of free or immobilised chitinase and -1,3-glucanase. It could be suggested that either immobilised Trichoderma or immobilised chitinase and -1,3-glucanase could be used in combination with benomyl to control plant pathogens.
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