Abstract
This work aimed to verify the effect in vitro, of Ascophyllum nodosum (AN) seaweed extract on the morphology and cellulolytic capacity of the fungus Fusarium oxysporum f. sp. vasinfectum (FOV). Thus, the fungus was placed in contact with different doses of the extract, being these: 0, 0.5, 1.0, 2.0, 4.0 and 8.0%. It was verified that the product, with increasing doses, progressively induced mycelial growth of the fungus, as measured by the diameter of the colonies and fresh mass of mycelium grown in PD (potato-dextrose) culture medium. This result was also corroborated by the progressive increase in the activity of the β-1,3-glucanase and chitinase enzymes required during the hypha elongation process. However, the AN extract progressively reduced FOV sporulation with increasing doses. Furthermore, the cellulolytic capacity of the phytopathogen was significantly reduced in the presence of the algae extract, which was measured by the activity of the enzymes endo-β-1,4-glucanase, exo-β-1,4-glucanase and β-glucosidase. Thus, these facts constitute important information for the management of fusariosis, since the inhibition of sporulation and decreasing degradation capacity of the cellulose by the pathogen, can translate into declined disease in compatible host-pathogen interactions.
Highlights
The genus Fusarium contains some of the most important phytopathogenic fungi species for world agriculture (Dean et al, 2012)
Algal polysaccharides present in the species, are identified as agents that inhibit the germination of the infectious propagules of several phytopathogens (Khan et al, 2011; Stadnik & Freitas, 2012) and, since these molecules are the probable agents for inhibiting the germination of these structures, they can be pointed out as the possible cause of the decrease in the germination of F. oxysporum f. sp. vasinfectum in the presence of the extract, observed in the results described here
Specific enzymes participate in the biosynthesis of the chitin and glucan molecules that will make up the cell wall (Adams, 2004)
Summary
The genus Fusarium contains some of the most important phytopathogenic fungi species for world agriculture (Dean et al, 2012). Other species of this genus are, admittedly, important producers of mycotoxins and, still others, are becoming worrisome pathogens for humans (van Diepeningen & Hoog, 2016). Chitinases and β-1,3-glucanases are the enzymes responsible for catabolism of the cell wall The latter, in turn, being less rigid can, this way, grow. After this process, the activity of cell wall degradation enzymes
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
