Antifungal efficacy of Moringa oleifera leaf and seed extracts against Botrytis cinerea causing gray mold disease of tomato (Solanum lycopersicum L.)

Abstract

Drawbacks associated with the use of chemical fungicides to control plant pathogenic fungi such as Botrytis cinerea stimulate the need for alternatives. Therefore, the present study was carried out to determine the antifungal potentials of Moringa oleifera extracts against B. cinerea. Phytochemical analysis using qualitative chemical tests revealed the presence of huge amount of crucial phytochemicals compounds like phenolic compounds, alkaloids and saponins in the M. oleifera leaf extract. Antifungal bioassay of the crude extracts indicated better mycelial growth inhibition by methanol leaf extract (99%). The minimum inhibitory concentration (MIC) was 5 mg/ml with 100% spore germination inhibition and minimum fungicidal concentration (MFC) was 10 mg/ml with 98.10% mycelial growth inhibition using broth micro dilution and poisoned food techniques. Gas chromatography–mass spectrometry (GC-MS) analysis led to the identification of 67 volatile chemical compounds in the leaf extract with 6-decenoic acid (Z)- (19.87%) was the predominant compound. Further chemical elucidation of the crude extracts performed by liquid chromatography with tandem mass spectrometry (LC-MS/MS) showed the presence of non-volatile chemical compounds, mostly flavones, flavonoids and phenolic acids (i.e. quercetin and kaempferol). Scanning electron microscopy and transmission electron microscopy analysis showed positive effect of M. oleifera leaf extract on the treated conidia and mycelium of B. cinerea. Findings revealed that irreversible surface and ultra-structural changes with severe detrimental effects on conidia and mycelium morphology compared to control treatment. Overall findings suggested that M. oleifera leaf extract is a promising candidate for biological control of fungal pathogens, thus limiting overdependence on chemical fungicides.

Control of Postharvest Gray Mold at Strawberry Fruits Caused by Botrytis cinerea and Improving Fruit Storability through Origanum onites L. and Ziziphora clinopodioides L. Volatile Essential Oils

“…Antifungal activities of the essential oils of O. onites (OO) and Z. clinopodioides (ZC) were tested with the poisoned food technique, as suggested by several previous studies [32,33], with slight modifications. Four different concentrations of both oils (0.25, 0.50, 1.00 and 2.00 mL/L) were prepared by adding the required amount of essential oils containing 1:2 (v/v) of Ethanol (70%) [20] to cooled (45 • C) molten PDA and rotating in a sterile Erlenmeyer flask.…”

Bioactivity of plant extracts from caatinga on cowpea weevil, Callosobruchus maculatus (Coleoptera: Chrysomelidae: Bruchinae)

“…These results suggest that some of the biological variables of C. maculatus, such as oviposition or growth and development of the progeny throughout its phases, were possibly influenced by the presence of secondary metabolites in the plant extracts. Thus, saponins present in Z. joazeiro (Nascimento et al, 2016) and M. oleifera (Ahmadua et al, 2021) probably influence the number of males and females of C. maculatus. Saponins act on insects by interfering with reproduction, causing developmental changes specifically in molting process and reducing food intake (Silva et al, 2012;Pineda-Cortel et al, 2019).…”

Essential Oils from Fruit and Vegetables, Aromatic Herbs, and Spices: Composition, Antioxidant, and Antimicrobial Activities

“…This result is comparable with those of other researchers, such as the case of Grul'ová et al [85] that reported complete inhibition of B. cinerea with 500 ppm oregano EO, and more than 80% with 100 ppm of oil incorporated into Potato Dextrose Agar. B. cinerea is a phytopathogen that causes the grey mould disease in more than 200 crop species worldwide such as grapes, cucumbers, tomatoes, strawberries, and leading to vast economic losses due to the severe damage in pre-and post-harvest [86,87]. Control strategies are carried out including chemical control, resistance induction and biological control.…”

“…Benzimidazoles, dicarboximides, phenylpyrroles, aromatic hydrocarbons, and phenylcarbamates are the main chemical fungicides used to control it [88]. In addition to B. cinerea is a phytopathogen that causes the grey mould disease in more than 200 crop species worldwide such as grapes, cucumbers, tomatoes, strawberries, and leading to vast economic losses due to the severe damage in pre-and post-harvest [86,87]. Control strategies are carried out including chemical control, resistance induction and biological control.…”