Significance of secondary metabolites and enzymes secreted by <i>Trichoderma atroviride</i> isolates for the biological control of Phomopsis canker disease

Abstract

Phomopsis theae Petch, the causative agent of Phomopsis canker diseases, is one of the major constrain in tea plants. The present study deals with development of efficient biological control agent against canker based on the secretion of several secondary metabolites and defense enzymes under in vitro conditions. Among the isolates evaluated, the antifungal compounds obtained from Tv1 Trichoderma atroviride was able to inhibit the growth of pathogen and showed 100% inhibition at concentration of 500 ppm. Synthesis of extracellular enzymes such as amylase, cellulase, polygalacturonase, protease and chitinase correlate with the antagonist activity of the isolates and maximum enzymatic activity was observed for Tv1 isolates followed by Tm3 and Tc3 isolates. The antifungal compounds responsible for the biological control activity were characterized through gas chromatography - mass spectroscopy (GC-MS) analysis.

Key words: Trichoderma atroviride, Phomopsis theae, tea plants, antifungal compounds, enzymatic activity.