Effect of volatile and non-volatile inhibitory compounds of rhizosphere fungal antagonistic microbes on the growth and development of chilli wilt pathogen Fusarium oxysporum

Abstract

Rhizospheric fungal antagonists can act as potential biocontrol agents towards fungal pathogens. They show antagonistic activity against phytopathogen by production of volatile and non volatile metabolites. In vitro assessments revealed their antibiosis and mycoparasitic ability to affect growth of the pathogen. This study explored the potential of rhizospheric fungal antagonists in controlling the wilt pathogen Fusarium oxysporum due to production of toxic volatile and non volatile metabolites. A total of twenty rhizospheric microbes were isolated from healthy chilli plants out of which eight fungal antagonists were tested for their ability to inhibit the growth of the pathogen Fusarium oxysporum by production of volatile and non volatile inhibitory metabolites. Among them four promising antagonists were tested RFA 2 showed the highest mycelial inhibition of the pathogen (24.35% and 74.5%) followed by RFA 4(17.29% and 60.47%) and RFA 1 (5.17% and 31.76%), whereas RFA 3 showed less inhibitory effect (2.35% and 22%) by production of volatile and non volatile inhibitory compounds respectively after seven days of inoculation.(Table-1). All the tested rhizospheric fungal antagonists showed positive results by significantly reducing the growth of pathogen.