Natural occurrence of nivalenol and mycotoxigenic potential of Fusarium graminearum strains in wheat affected by head blight in Argentina

Abstract

The principal agents of Fusarium head blight in the main cropping area of Argentina were investigated in heavily infected samples. The ability of the isolates to produce trichothecenes was determined by GC and HPLC. Fusarium graminearum was the predominant species and of 33 isolates, 10 produced deoxinivalenol (DON) (0.1-29 mg kg ), 10 produced Fusarenone X (0.1-2.4 mg kg -1 ) and 7 produced zearalenone (0.1-0.6 mg kg -1 ). These results suggest that F. graminearum strains isolated from the wheat growing regions in Argentina belong to DON chemotype. Although some strains produced both deoxinivalenol and nivalenol, nivalenol was produced in lower levels. The natural occurrence of nivalenol in wheat affected by head-blight collected in the main production area during two years (2001)(2002) was also determined. From 19 samples 13 were contaminated with deoxinivalenol in a range of 0.3 to 70 mg kg -1 and 2 samples with both deoxinivalenol (7.5 and 6.7 mg kg -1 ) and nivalenol (0.05 and 0.1 mg kg -1 ), respectively. This is the first report of natural occurrence of nivalenol in wheat cultivate in Argentina.

Fungal diversity and natural occurrence of fusaproliferin, beauvericin, deoxynivalenol and nivalenol in wheat cultivated in Santa Fe Province, Argentina

“…A relevant relationship between DON presence and Fusarium species belonging to section Discolor (F. graminaerum and F. culmorum) in Zone II was observed, since 4 out of 11 positive samples for DON reached concentrations between 7.9 and 9.5 mg kg −1 . Our findings agree with different authors for other areas of Argentina (González et al 1996(González et al , 2008Dalcero et al 1997b;Fernández Pinto et al 2008). These authors found a strong correlation between the presence of F. graminearum and DON concentration.…”

“…Each analysis was performed with a 20-μL loop, water (A) + acetonitrile (B) as eluent solvents (gradients of 0 min 10% B, 10 min 100% B, 13 min 100% B, 16 min 10% B, 20 min 10% B), and a total flow of 1 mL min −1 at 219 nm wavelength. All analyses were run in triplicate (Fernández Pinto et al 2008).…”

“…DON is the toxin most commonly found in Argentinean wheat (Quiroga et al 1995;González et al 1996;Dalcero et al 1997a). The natural occurrence of NIV in wheat samples cultivated in Argentina has also been reported (Fernández Pinto et al, 2008). Two other toxic metabolites are beauvericin (BEA) (Krska et al 1996) and fusaproliferin (FP).…”

“…The incidence of toxigenic Fusarium spp. and their toxins in this large cultivated area has been scarcely studied (Fernández Pinto et al 2008).…”

Monitoramento e nível de ingestão de desoxinivalenol por trigo

“…Oliveira et al (2002), analisando farinha de trigo e produtos de panificação comercializados em cidades de Minas Gerais, detectaram níveis de 40 a 1205 µg/kg em farinha, 78 a 780 µg/kg em pão de sal, 113 a 289 µg/kg em pão de forma e não-detectado em panetone. Pinto et al (2008) Um aumento de positividade e níveis de DON tem sido observado em trigo brasileiro nos últimos anos (OLIVEIRA et al, 2002;LAMARDO;NAVAS;SABINO, 2006;CALORI-DOMINGUES et al, 2007). Todavia, a contaminação por DON depende das condições meteorológicas, causando variações entre diferentes safras, devido a condições favoráveis ao desenvolvimento fúngico.…”