In Vitro Antifungal Activity of Different Plant Hormones on the Growth and Toxicity of Nigrospora Spp. on Date Palm (Phoenix dactylifera L.)

Abstract

Objective:The profound negative impact of chemical fungicides on human and animal health, as well as, the whole agroecosystem encouraged tremendous efforts to find alternative approaches to suppress the growth of plant pathogens. Method:Recently, plant hormones have been considered to reduce fungal severity. Five different plant hormones namely 2, 4-D (2,4-Dichlorophenoxyacetic acid); BAP (6-Benzylaminopurine); Dicamba (3,6-Dichloro-2-methoxybenzoic acid, 3,6-Dichloro-o-anisic acid); IAA (Indole-2-acetic acid) and SA (Salicylic acid) were selected to examine their antifungal activity against the growth of two species of date palm fungal pathogen Nigrospora spp. Results:Results showed that SA at 50 ppm was sufficient to inhibit the mycelium growth of N. oryzae completely, while with N. sphaerica; the treatments of 2, 4-D (40-50 ppm) and SA (40-50 ppm) led to similar complete inhibition results of mycelium growth. The data of BAP and IAA indicated no toxic effect toward mycelium growth of the pathogens. Similar trends of results have been obtained for phytotoxicity bioassay which performed on detached date palm leaves, 2, 4-D and SA at 30 ppm led to a complete inhibition for the production of toxins in the culture of N. oryzae and N. sphaerica. Conclusion:58% significant reduction in toxin production was obtained with Dicamba 30 ppm. Results presented here reveal the antifungal activity of different plant hormones in in vitro experiments, and are important to examine their efficiency in farther field studies on date palm.

Interconnectedness, length and viability of arbuscular mycorrhizal mycelium as affected by selected herbicides and fungicides

“…Dicamba and other synthetic auxin herbicides mimic IAA effects and, when present at high concentrations in tissues, elicit distorted cell division and expansion, resulting in systemic plant structural alteration. Inhibitory activity of dicamba on fungal growth was reported for Nigrospora oryzae and Nigrospora sphaerica in vitro (Abass, 2017) and for Rhizoctonia cerealis in vivo (Gisi, 1996), while other hormonal herbicides like MCPA exerted a reduction of AMF root colonization (Garcia-Romera and Ocampo, 1988). Interestingly, fungitoxicity of dicamba on PI mycelial growth was dependent on the concentration tested, since at low concentrations (i.e.…”

Dimethylformamide Inhibits Fungal Growth and Aflatoxin B1 Biosynthesis in Aspergillus flavus by Down-Regulating Glucose Metabolism and Amino Acid Biosynthesis

“…Safe and efficient natural substances for preventing and controlling A. flavus growth and AFs production are necessary. Essential and plant hormone possessing potent anti-microbial, antioxidant activities, were applied to agricultural industry [13,14]. However, some fungicides have low solubility in general solvents.…”

Growth regulators promote soybean productivity: a review

“…( cinerea and allii ) , Penicillium expansum , Colletotrichum dematium , Alternaria alternata , Xanthomonas oryzae pv. oryzae ( Xoo ), Sclerotinia sclerotiorum and Magnaporthe oryzae among others ( Abass, 2017 ; Bucio-Villalobos et al, 2005 ; Qin et al, 2003 ). The growth inhibition reduced disease incidences such as mold disease in cucumber ( Al-Masri et al, 2002 ), early blight in potatoes ( Michniewicz & Rozej, 1988 ), botrytis blight in cut rose flowers ( Shaul, Elad & Zieslin, 1995 ), and improved resistance to bacterial leaf blight and blast disease in rice ( Shimono et al, 2007 ).…”