Biological Control and Plant Growth Promotion by Volatile Organic Compounds of Trichoderma koningiopsis T-51

Abstract

<i>Trichoderma</i> spp. are widely used in plant disease control and growth promotion due to their high efficacy and multiple biocontrol mechanisms. <i>Trichoderma koningiopsis</i> T-51 is an effective biocontrol agent against gray mold disease by direct contact. However, the indirect physical contact biocontrol potential of <i>Trichoderma</i> spp. is not clear. In this study, the volatile organic compounds (VOCs) produced by T-51 showed high inhibitory activity against plant pathogenic fungi <i>Botrytis cinerea</i> and <i>Fusarium oxysporum</i>. The percentage of <i>B. cinerea</i> and <i>F. oxysporum</i> mycelial growth inhibition by T-51 VOCs was 73.78% and 43.68%, respectively. In both <i>B. cinerea</i> and <i>F. oxysporum</i>, conidial germination was delayed, and germ tube elongation was suppressed when exposed to T-51 VOCs, and the final conidial germination rate of <i>B. cinerea</i> decreased significantly after T-51 treatment. The VOCs from T-51 reduced the <i>Botrytis</i> fruit rot of tomato compared with that noted when using the control. Moreover, the T-51 VOCs significantly increased the size and weight of <i>Arabidopsis thaliana</i> seedlings. Twenty-four possible compounds, which were identified as alkenes, alkanes, and esters, were detected in VOCs of T-51. These results indicate that <i>T. koningiopsis</i> T-51 can exert biological control by integrating actions to suppress plant disease and promote plant growth.