Induction of defence related enzymes and biocontrol efficacy of Trichoderma harzianum in tomato plants infected with Fusarium oxysporum and Fusarium solani

Abstract

<p>Fusarium wilt of tomato plants caused by<em> Fusarium oxysporum </em>Schlecht. emend. Snyder &amp; Hansen and<em> Fusarium solani</em> (Mart.) Sacc. are serious problem limiting tomato production worldwide. Biological control has emerged as one of the most promising alternatives to chemical fungicides. The biological control capability of a <em>T. harzianum </em>isolate against <em>F. solani</em> and <em>F. oxysporum</em> has been investigated. It inhibited colony growth of two <em>Fusarium</em> species by more than 80 % in dual culture tests. Results of greenhouse experiments revealed that disease severity in the tomato plants co-inoculated with <em>T. harzianum</em> was significantly lower than plants only infected with the <em>Fusarium</em> pathogens. Tomato plants inoculated with the antagonistic <em>T. harzianum</em> isolate, showed enhanced peroxidase and polyphenol oxidase activities in greenhouse experiments and increased resistance to <em>F. solani</em> and <em>F. oxysporum</em>. The <em>T. harzianum</em> isolate indirectly affected the <em>Fusarium </em>pathogens by enhancing plant defence.</p>