Assessment of the Fungicidal and Nematicidal Potential of Reichardia tingitana (L.) Roth on Phytopathogenic Fungi and Plant Nematode

Abstract

The primary concern was the removal of numerous soil fumigants and nematicides due to their potential risks to human and environmental safety. Fungal pathogens can cause serious diseases in humans and animals. Among these, root-knot nematodes such as Meloidogyne incognita and Tylenchulus semipenetrans pose a significant threat, leading to substantial damage and yield reduction in various economically important plants. Therefore, this study aimed to assess the fungicidal and nematicidal activities of the ethanol extract (EE) and lupeol (L), the major isolates from the aerial parts of Reichardia tingitana L. Roth (Asteraceae), against Aspergillus flavus and plant-parasitic nematodes. Antifungal actions of EE (10-120 ppm) and L (23.4-281.2 µM) were evaluated through in vitro and in vivo growth assays, spore germination inhibition assays, and the efficacy of inhibiting pod and kernel infection. Nematicidal activity of EE and L was tested by preparing cultures containing egg masses of nematode species M. incognita from infected eggplants and T. semipenetrans from infected citrus roots, using concentrations of 2.5, 5, 10, 20, 40, 80, and 120 ppm. Results showed that R. tingitana (EE) and (L) exhibited nematostatic or nematicidal effects on nematode viability, egg hatch in vitro, and development and reproduction in vivo. Lupeol was particularly effective in inhibiting the colonization of A. flavus in peanuts. EE and L demonstrated high toxicity against nematodes in laboratory exposure and were effective in controlling nematode infestation in eggplant roots for 45 days. Improvement in plant growth parameters, including shoot and root length and weights, varied and was proportional to the doses of EE and L treatments. The antifungal and bio-nematicide effects of the ethanol extract from the aerial parts of R. tingitana were superior to those of lupeol, which could be attributed to the synergistic effect of phytochemicals in the ethanol extract. Both EE and L have potential applications as antifungal and bio-nematicide agents.