Prevalence and Management of Phytopathogenic Seed-Borne Fungi of Maize

Abstract

Seed-borne fungi are solemn and deleterious pathogens capable of causing significant losses of quantity and quality losses in maize seeds and seedlings. They infect the crop at all points of the production chain from farms to stores. A yield loss of up to 50% can be encountered. Currently, chemical control of the disease is being implemented, though it is accompanied by several negative effects. This study aimed at identifying seed-borne fungi of maize and effective management options. A deep-freezing blotter method and morphological identification of the fungal species were implemented. The seed-borne fungi detected were Fusarium verticillioides, Aspergillus flavus, Aspergillus niger, Penicillium spp., Rhizopus spp., and Curvularia spp. However, in farmer-saved seeds, fungal incidences were significantly higher (p < 0.01) than in certified seeds. To identify more effective management options, the efficacy of water and ethanol-extracted bio-fungicides from three plant species, namely, neem (Azadirachta indica), ginger (Zingiber officinale), and coffee (Coffea arabica) were evaluated. From in vitro assays, ethanol-extracted bio-fungicides have a 100% inhibitory effect on fungal growth, whilst the inhibitory effects of water-extracted bio-fungicides are 55.88% (Azadirachta indica) and 46.31% (Zingiber officinale), followed by 5.15% (Coffea arabica). For the case of an in vivo assay, maize seeds treated with water-extracted bio-fungicides have higher seed germination and seedling vigor percentages. For germination, seeds treated with water-extracted bio-fungicides have higher percentages (neem and ginger (90%) followed by coffee (72.5%)) than ethanol-extracted bio-fungicides (neem (0%), ginger (2.5%), and coffee (0%)). A similar observation is made for seedling weight. Therefore, the tested water-extracted bio-fungicides can be used in treating seeds before sowing them. Further studies on effective methods of extracting bioactive compounds, and improving their shelf life, are recommended.

In vitro and in vivo antifungal activity of chitosan and identification of potentially toxigenic fungi in stored maize of Nayarit, Mexico

“…is one of the fungi that occur most frequently followed by the genus Penicillium spp., while in the field the highest incidence is of the genus Fusarium spp. (Akonda et al, 2016;Erasto et al, 2023;González-Jartín et al, 2022;Gulbis et al, 2016;Muhammad et al, 2019;Odjo et al, 2022;Pfliegler et al, 2020;Qi et al, 2023).…”

“…According to the BLAST search, the A1 strain showed 100% coverage and 100% identity with A. niger, the P1 strain had 100% coverage and 100% identity with P. funiculosum, and the F1 strain had 99% coverage and 99.57% identity with F. verticillioides. Mycotoxin-producing pathogenic fungi, such as A. niger, P. funiculosum, and F. verticillioides, are often isolated from cereals, particularly maize, throughout the world (Erasto et al, 2023;González-Jartín et al, 2022;Muhammad et al, 2019;Odebode et al, 2020;Odjo et al, 2022;Pfliegler et al, 2020;Qi et al, 2023).…”

“…On the other hand, they represent a potential health risk due to the production of mycotoxins. (Erasto et al, 2023;González-Jartín et al, 2022;Kolawole et al, 2021;Ravichandra, 2022). Mycotoxins are secondary metabolites with varied toxic capacities; chronic exposure to them has been related to hepatotoxicity, nephrotoxicity, neurotoxicity, genotoxicity, teratogenicity, and immunomodulation (Abrehamed et al, 2023IARC, 1993.…”

Molecular identification and prevalence of fungal contaminants in seeds of semi-annual crops

“…Se debe prestar especial atención a los hongos productores de micotoxinas presentes en la semilla como Aspergillus, Penicillium y Fusarium. Reportes previos indican que sembrar semillas infectadas con hongos patógenos productores de micotoxinas contribuye al inóculo de hongos micotoxigénicos en el suelo, los cuales luego contaminan el grano cosechado con diversas micotoxinas en el siguiente ciclo de producción (Erasto et al, 2023).…”

“…Esta diseminación ha llevado a riesgos más elevados, ya que estos patógenos encuentran nuevos entornos y hospederos en los que establecerse (Dell'Olmo et al, 2023). Una consecuencia particularmente preocupante de este fenómeno es el potencial de pérdidas de rendimiento de hasta un 50%, atribuidas a la actividad de hongos transmitidos por semillas responsables de provocar enfermedades fúngicas (Erasto et al, 2023). En este contexto, la identificación y caracterización de contaminantes fúngicos es un componente esencial del manejo enfocado a reducir la afectación en la calidad de semilla (Naqvi & Rehman, 2013).…”