Plant Growth-Promoting Fungi as Biocontrol Tool against Fusarium Wilt Disease of Tomato Plant

Plant growth-promoting fungi (PGPF) improve plant health and resist plant pathogens. The present study was carried out to biocontrol tomato Fusarium wilt using PGPF through antifungal activity and enhance tomato plant immune response. Four PGPF were identified genetically as <i>Aspergillus flavus</i>, <i>Aspergillus niger</i>, <i>Mucor circinelloides and Pencillium oxalicum</i>. In vitro antagonistic activity assay of PGPF against <i>Fusarium</i><i>oxysporum</i> was evaluated, where it exhibited promising antifungal activity where MIC was in the range 0.25-0.5 mg/mL. Physiological markers of defense in a plant as a response to stimulation of induced systemic resistance (ISR) were recorded. Our results revealed that <i>A. niger</i>, <i>M. circinelloides</i>, <i>A. flavus</i> and <i>P. oxalicum</i> strains significantly reduced percentages of disease severity by 16.60% and 20.83% and 37.50% and 45.83 %, respectively. In addition, they exhibited relatively high protection percentages of 86.35%, 76.87%, 56.87% and 59.06 %, respectively. With concern to the control, it is evident that the percentage of disease severity was about 87.50%. Moreover, the application of <i>M. circinelloides</i>, <i>P. oxalicum</i>, <i>A. niger</i> and <i>A. flavus</i> successfully recovered the damage to morphological traits, photosynthetic pigments' total carbohydrate and total soluble protein of infected plants. Moreover, the application of tested PGPF enhanced the growth of healthy and infected tomato plants.