Journal of Agricultural Science and Food Research
Open Access

Abstract

Biostimulation of Tomato Growth and Suppression of Fusarium Crown and Root Rot Disease Using Fungi Naturally Associated to Lycium arabicum

Nefzi Ahlem, Aydi Ben Abdallah Rania, Jabnoun-Khiareddine Hayfa, Ammar Nawaim, Somai Lamia, Hamada Walid, Haouala Rabiaa and Daami-Remad Mejda

Seven fungal agents were isolated from native Lycium arabicum plants growing in the Tunisian Centre-East and were screened for their ability to inhibit Fusarium oxysporum f. sp. radicis lycopersici (FORL) development and to promote plant growth. They were shown able to colonize tomato roots, crowns and stems. Seedlings inoculated or not with FORL and treated with these fungal isolates showed significant increments in all studied growth parameters (root length, shoot height, and fresh weight of roots and shoots). Tested as conidial suspensions or cell-free culture filtrates, I15 and I18 isolates were found to be the most active leading to 85.7-87.5% decrease in leaf and root damage index and to 93.6-98.4% lowered vascular browning extent over FORL-inoculated and untreated control. These two bioactive and growth-promoting isolates (I15 and I18) were microscopically and macroscopically characterized and identified using rDNA sequencing gene as being Alternaria alternata (MF693801) and Fusarium fujikuroi (MF693802). FORL mycelial growth was inhibited by 36.4-77.4 and 62.2-81% using their conidial suspensions and cell-free culture filtrates, respectively. Both isolates showed chitinolytic, proteolytic and amylase activities but lipolytic activity was displayed by F. fujikuroi (MF693802) only. To the best of our Knowledge, this is the first study that shows the potential use of fungi naturally associated to L. arabicum for suppression of Fusarium Crown and Root Rot and enhancement of tomato growth.