Influence of temperature, humidity duration and growth stage on the infection and mycotoxin production by Fusarium langsethiae and Fusarium poae in oats

Abstract

High occurrence of Fusarium poae (FP) and Fusarium langsethiae (FL) and their mycotoxins nivalenol (NIV) and T‐2/HT‐2 have been observed in Swiss oats. Early prediction of mycotoxin levels is important for farmers and the cereal industry to minimize the risk of contaminated food and feed. Therefore, climate chamber experiments were conducted to investigate the influence of different temperatures (10, 15, 20 °C) and durations (4, 8, 12 h) at 99% relative humidity (RH) on the infection of oats with FP and FL. In addition, to discover the most susceptible period of oats, artificial FL inoculations were conducted at different growth stages. Field experiments were performed to observe the dispersal of these fungal species within the field and to investigate the weather conditions that influence the dispersal. The climate chamber experiments revealed higher contamination with NIV and T‐2/HT‐2 in the 10 °C treatments and with a prolonged humidity duration of 12 h 99% RH. Inoculations of oat plants at early (DC 61) and mid (DC 65) anthesis, led to higher FL infection and T‐2/HT‐2 accumulation in the grains compared with treatments at earlier growth stages, which might be due to an increased susceptibility during anthesis. No indication for spore dispersal was observed in the field experiments. The results obtained, together with the cropping factors that influence infection and mycotoxin production, could be used as a first step in developing forecasting models to predict the contamination of oats with the mycotoxins NIV and T‐2/HT‐2.

Investigating the Efficiency of Hydroxycinnamic Acids to Inhibit the Production of Enniatins by Fusarium avenaceum and Modulate the Expression of Enniatins Biosynthetic Genes

“…Such a lasting effect could be explained by the strong imprint of germination process on the biosynthesis of mycotoxins [17,29]. Our findings corroborate previous studies that have led to the conclusion that FER was the most potent phenolic acid with antifungal and anti-mycotoxin activity against various Fusarium species including Fusarium graminearum, Fusarium verticillioides, Fusarium poae, Fusarium langsethiae, and Fusarium sporotrichioides [20,25,30]. According to our results, FER that has been suggested to play a pivotal role in cereal resistance to F. graminearum and to deoxynivalenol accumulation [24,31] could also contribute to the mechanisms employed by plants to counteract the infection by F. avenaceum and contamination with ENNs.…”

Contrasting responses of T-2, HT-2 and DON mycotoxins and Fusarium species in oat to climate, weather, tillage and cereal intensity

“…Injecting spores at boot stage, Divon et al (2012) could create head infections, but Imathiu et al (2013) and Opoku et al (2013) found that the primary infections that later lead to toxin accumulation occurred largely at head emergence and anthesis. Schöneberg et al (2019) found that inoculation with spores at GS61 and GS65 led to high DNA content of FL in oat grains, whereas earlier inoculations at GS51 and GS55 led to very low content.…”

“…The optimal temperature range for infection of durum wheat spikes was 15-20°C and for growth 20-30°C, peaking at 24-25°C. In experiments by Schöneberg et al (2019) in Austria a lower optimum for infection of oat by FL was observed: inoculations at the beginning of anthesis (GS61) and at mid-anthesis (GS65) under 99% relative humidity (RH) at 10°C led to clearly higher DNA content of FL than inoculations at 15 and 20°C; 4 h of 99% RH after spraying of spores were enough for successful infection. The optimum for sporulation of FL was 25°C (Nazari et al 2016).…”

Genome‐wide association mapping of Fusarium langsethiae infection and mycotoxin accumulation in oat (Avena sativa L.)

“…HT‐2 toxin was the main contributor to increase the total toxin (Table 2) probably because in oat T‐2 is quickly converted to HT‐2 as a result of the removal of the acetyl group at C‐4 position of T‐2 (Meng‐Reiterer et al., 2016). Previous field studies at field have shown that fungal biomass of F. langsethiae was correlated with T‐2 and HT‐2 concentration (Imathiu, Edwards, Ray, & Back, 2013a; Schöneberg et al., 2019). In this study, different results were observed, and this can be due to the diversity of oat cultivars studied in this study.…”