Symptoms of Fusarium graminearum infection in irrigated rice grains

Abstract

The fungus Fusarium graminearum was one of the first pathogens described as causing infections in rice; however, in Brazil, there is no description of its occurrence in panicles. The present study aimed to describe the symptoms caused by F. graminearum infection in irrigated rice grains. The experiment was conducted in a greenhouse in duplicate using the irrigated rice cultivar SCS 121CL and hybrid INOV CL at the R4 (flowering) stage. Two isolate of Fusarium graminearium species complex 15A (F. graminearium - 15-ADON) and FmNiv (F. meridionale - Nivalenol), was inoculated onto panicles by spraying with macroconidia and the development of symptoms was monitored until harvest. There was no difference in symptoms among isolates. Light brown spots were observed in the glumes three days after inoculation. These later evolved into brown lesions of irregular shape and size. The glume darkened to purple when the grains were in the filling stage (R6). On maturation, the glume showed dark brown coloration. Severely infected grains were shriveled and brittle.

Nationwide survey reveals high diversity of Fusarium species and related mycotoxins in Brazilian rice: 2014 and 2015 harvests

“…Occasionally, panicles in the field appear blighted due to infection by species of the F. graminearum species complex (FGSC), the main cause of Fusarium head blight of wheat and barley and Gibberella ear rot (GER) of maize (Kuhnem et al, 2016;Del Ponte et al, 2015). Symptoms of panicle blight appear sporadically in the south of Brazil and these have been reproduced in a controlled environment when panicles were challenged with FGSC inoculum (Scheidt et al, 2019). FGSC species produce mainly B-trichothecene (deoxynivalenol, nivalenol and their acetylates) and zearalenone mycotoxins (O'Donnell, Kistler, Tacke, & Casper, 2000).…”

Actividad antifúngica de compuestos fenólicos de tara (Caesalpinia spinosa) frente a Fusarium graminearum

“…Por su parte, especies del género Fusarium se consideran principalmente como hongos de campo (Villa et al, 2014); son de particular estudio porque pueden causar hasta el 90% de pérdidas en la cosecha (Briones, 2014) en monocultivos, como es el caso del arroz, y afectan la envoltura ocasionando la pudrición de la misma (Villanueva et al, 2013;Bigirimana et al, 2015). Los síntomas de Fusarium graminearum en etapa de floración del arroz son manchas de color café claro en las glumas; posteriormente, evolucionan a lesiones marrones de tamaño y formas irregulares; en la etapa de llenado, las glumas son de color purpura; y para la cosecha, los granos maduros tienen color marrón oscuro (Tabarelli et al, 2019). Actualmente, el control de microorganismos fitopatógenos se realiza mediante técnicas de agricultura convencional (De León et al, 2013), con efectos negativos para la salud humana y daños al medio ambiente.…”