Phytochemical analysis and antifungal activity of Azadirachta indica and Balanites aegyptiaca seed extracts against Fusarium oxysporum isolate on tomatoes

Abstract

Fusarium oxysporum is the causative agent of tomato wilt and is an important disease of tomato crops worldwide. Management through chemical fungicides causes serious environmental damage and human health. This study assesses the antifungal potential of biochemical compounds of Azadirachta indica and Balanites aegyptiaca seeds extracts identified by GC-MS analytical method against F. oxysporum. Acetone, methanol and aqueous extracts of A. indica and B. aegyptiaca at 15, 30 and 60 μL/mL concentrations and synthetic fungicide (3.33 g/L) were tested in vitro in triplicate. Mycelial growth and Minimum inhibitory concentrations (MIC50, MIC90) were evaluated 8 days after inoculation (DAI). As results, 55 and 34 phytochemical compounds were identified in seed extracts of A. indica and B. aegyptiaca respectively. Methanol extract of A. indica and B. aegyptiaca at 60 μL/mL concentration showed a total inhibition (100%) of F. oxysporum mycelial growth. Low MIC50 values were obtained with aqueous extract of A. indica (8.77 μL/mL) and methanol extract of B. aegyptiaca (17.91 μL/mL). The tentative action mode showed that the methanol extract of both plants induced wall lysis of F. oxysporum. These results suggest that A. indica and B. aegyptiaca seed extracts have potent antifungal activity and could be used as an alternative to control F. oxysporum. Keywords: Neem, desert date, bioactive compounds, mycelial growth, antifungal activity, Fusarium oxysporum