Five‐year survey uncovers extensive diversity and temporal fluctuations among fusarium head blight pathogens of wheat and barley in Brazil

Abstract

We conducted a five‐year survey (2011–2015) of barley and wheat fields in Paraná state, Brazil, obtaining 754 Fusarium isolates from spikes with fusarium head blight (FHB)‐symptoms. Multilocus genotyping and TEF‐1α gene sequence analyses confirmed the dominance of the F. graminearum species complex (FGSC, 75.7%), but F. poae (11.5%), as well as F. avenaceum and related members of the F. tricinctum species complex (FTSC, 8.1%) appeared as substantial contributors to FHB. Within the FGSC, F. graminearum of the 15‐ADON genotype was dominant (63%), followed by F. meridionale of the NIV genotype (23.1%), F. cortaderiae of the NIV (7%) or 3‐ADON (2.6%) genotypes, and F. austroamericanum (3.8%) of the 3‐ADON genotype. Substantial variation in pathogen composition was observed across years, with F. poae and F. meridionale frequencies significantly elevated in some years. Most F. poae strains produced DAS, diANIV, and butenolide, but not neosolaniol, T‐2, or HT‐2. All FTSC species produced moniliformin. Enniatin production was widespread among FTSC species, with the single F. acuminatum strain found to be the strongest producer of enniatins. Our findings confirm FGSC as a major contributor to FHB and expand considerably our knowledge of the presence, frequency, and conditions under which other pathogens may emerge, altering the spectrum of toxins that may accumulate in grain.

Fusarium graminearum species complex: A bibliographic analysis and web-accessible database for global mapping of species and trichothecene toxin chemotype

“…Higher FGSC species diversity was found in wheat crops grown at lower latitudes, near to or within subtropical environments (Pereira et al 2021;Umpiérrez-Failache et al 2013). This suggests that there is also an effect of climate in shaping species distributions, as posited previously by a modelling study (Backhouse 2014).…”

“…In wheat and barley, members of the FGSC cause Fusarium Head Blight (FHB), which re-emerged as a major concern throughout the world in the early 1990s (Goswami and Kistler 2004;McMullen et al 1997McMullen et al , 2012. Numerous surveys of disease incidence and severity, pathogen population diversity, and mycotoxin contamination have been conducted during the past three decades in the main cereal-growing regions of the world where FHB epidemics have occurred (Cowger et al 2019;Pereira et al 2021; van der Lee et al 2015;Vogelgsang et al 2019).…”

Characterization of Fusarium acuminatum: A Potential Enniatins Producer in Tunisian Wheat

“…In a previous work where F. acuminatum 33T was cultivated on FDM-agar medium, its level of ENNs’ production was 10-fold higher than for a strain of F. avenaceum cultivated under the same conditions [ 14 ]. Comparing the single F. acuminatum strain with 30 F. avenaceum they isolated in a survey of barley and wheat fields in Paraná state, Brazil, Peirera et al [ 41 ] found F. acuminatum to be the strongest producer of ENNs. Despite its low occurrence, F acuminatum has to be considered as a significant source of mycotoxin contamination of crops, due to its high potential for ENNs’ production.…”

Effect of Gliding Arc Plasma Jet on the Mycobiota and Deoxynivalenol Levels in Naturally Contaminated Barley Grains

“…However, the growth of filamentous fungi in barley is a concern for the food industry and it mainly happens due to inappropriate management during the pre-harvest, transportation, and storage of cereal grains [ 27 ]. In addition, climatic conditions associated with insect infestation and intrinsic factors of the raw material are considered relevant, as they may favor the development of these microorganisms and mycotoxin production, which are toxic secondary metabolites mainly produced by the genera Alternaria , Aspergillus , Fusarium , and Penicillium , with the Fusarium graminearum species complex (FGSC) often reported in barley (dominant species, with more than 80% frequency) [ 28 , 29 , 30 ]. Another species that is important to study is F. meridionale , which significantly contributes to the Fusarium Head Blight (FHB) disease of wheat in Paraná and Rio Grande do Sul, Brazil.…”