Infection timing affects Fusarium poae colonization of bread wheat spikes and mycotoxin accumulation in the grain

Authors: FRANCESCO, TINI - University Of Perugia; COVARELLI, LORENZO - University Of Perugia; Cowger, Christina; SULYOK, MICHAEL - University Of Natural Resources And Life Sciences, Vienna; BENINCASA, PAOLO - University Of Perugia; BECCARI, GIOVANNI - University Of Perugia

Submitted to: Field Crops Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/8/2022
Publication Date: 5/10/2022
Citation: Francesco, T., Covarelli, L., Cowger, C., Sulyok, M., Benincasa, P., Beccari, G. 2022. Infection timing affects Fusarium poae colonization of bread wheat spikes and mycotoxin accumulation in the grain. Field Crops Research. 12002. https://doi.org/10.1002/jsfa.12002.
DOI: https://doi.org/10.1002/jsfa.12002

Interpretive Summary: Fusarium poae is one of the most common Fusarium head blight (FHB) causal agents in wheat. This species can biosynthesize a wide range of mycotoxins, in particular nivalenol (NIV). In FHB epidemiology, infection timing is important for disease occurrence, kernel development, symptom appearance and mycotoxin accumulation in grain. The present study explored, both in a controlled environment and in a 2-year field plot experiment in Central Italy, the influence of five infection timings (from beginning of flowering to medium milk growth stage) on F. poae colonization and mycotoxin accumulation in bread wheat spikes (spring cv. A416 and winter cv. Ambrogio).

Technical Abstract: Fusarium poae is one of the most common Fusarium head blight (FHB) causal agents in wheat. This species can biosynthesize a wide range of mycotoxins, in particular nivalenol (NIV). In FHB epidemiology, infection timing is important for disease occurrence, kernel development, symptom appearance and mycotoxin accumulation in grain. This study explored, both in a controlled environment and in a 2-year field plot experiment in Central Italy, the influence of five infection timings (from beginning of flowering to medium milk growth stage) on F. poae colonization and mycotoxin accumulation in bread wheat spikes. FHB symptoms on spikes and kernels were visually evaluated. In addition to grain yield, F. poae biomass accumulation in the grain and the chaff was determined by qPCR. Finally, secondary metabolites in the grain were analyzed by LC-MS/MS. Both climate chamber and field experiments showed that early infection timings (from beginning of flowering to full flowering) especially favoured F. poae colonization and accumulation of its mycotoxins (particularly NIV) in grain. By contrast, later infection timings (watery ripe and medium milk) reduced F. poae development and mycotoxin levels. The time window of host susceptibility in the field was shorter than that observed in controlled conditions. Symptom expression in kernels also differed among infection timings. In general, F. poae biomass was higher in the chaff than in the grain. These results enhance knowledge of a common member of the FHB complex worldwide, and could be useful in forecasting the risk of F. poae infection and mycotoxin contamination.