In Vitro Inhibition of Cellulolytic Enzymes of Fusarium Oxysporum by Trichoderma spp and Pseudomonas Fluorescens on Arachis Hypogaea L

P Rajeswari

doi:10.3126/ijasbt.v3i1.12138

Abstract

In an attempt to develop biocontrol system for management of Fusarium wilt in groundnut, Trichoderma viride, Trichoderma harzianum,and Pseudomonas fluorescens were evaluated for their antagonistic activity against Fusarium oxysporum in vitro. .Fusarium wilt diseasescaused by the fungus Fusarium oxysporum lead to significant yield losses of crops. Experiments were conducted on the effect of culture filtratesof T.viride (1%), T. harzianum (1.5%), and P. fluorescens (2%) on the in vitro inhibition of cellulolytic enzymes of Fusarium oxysporum. Theactivity of 1,4 endoglucanases, 1,4exoglucanase Cellobiase produced by Fusariumoxysporum was higher, when compared to control.Maximum inhibition of above Cellulolytic enzymes (1, 4 endoglucanases, 1,4exoglucanase, Cellobiase) was shown by T. viride treatment wasfollowed by T. harzianum and P. fluorescens. Of all the treatments, T. viride treatment showed higher rate of inhibition of Cellulolytic enzymesof Fusarium oxysporum followed by that of T. harzianum and P. fluorescens.This present study indicates that culture filtrate of T.viride(1%)is the best biocontrol agent in the inhibition of Fusarium oxysporum causing Fusarium wilt of Arachis hypogaea .LDOI: http://dx.doi.org/10.3126/ijasbt.v3i1.12138 Int J Appl Sci Biotechnol, Vol. 3(1): 106-110

Highlights

Arachis hypogaea L. is an important crop in many areas of the world and is found throughout the tropical, subtropical, and warm temperate regions between 40° north and 40° south latitudes
T. harzianum P. fluorescens p< 0.001 as compared to control specific activity units (SAU)= micro g of maltose equivalent liberated /h The values within a column followed by different letters are significantly different according to Tukey’s HSD multiple range test (TMRT) at 5% level of significance (n=3)
The highest cellobiase activity was observed in case of control (40.88SAU) followed by the enzyme sources obtained from P. fluorescens (16.38SAU) and T.harzianum(14.76SAU) The lowest rate of enzyme activity was observed in T. viride-treated enzyme source (13.54SAU)

Summary

Introduction

Arachis hypogaea L. is an important crop in many areas of the world and is found throughout the tropical, subtropical, and warm temperate regions between 40° north and 40° south latitudes. To gain entrance to plant cells, fungi generally secrete a mixture of hydrolytic enzymes including cutinases, cellulases, pectinases and proteases .After penetration, the fungus often secretes toxins or plant hormone- like compounds that manipulate the plants’ physiology to the benefit of the pathogen (Knogge, 1996). This is often achieved through the production of phytotoxins with varying degrees of specificity towards different plants (Walton, 1994).Fusarium oxysporum produces several enzymes that act upon the pectic and cellulose components of cell walls of host plant (Agrios, 1997). Results of the investigation done by Fisher (1965) have shown that cellulolytic enzyme production is induced in surface rot and Fusarium wilt of sweet potato

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