The prevalence and impact of Fusarium head blight pathogens and mycotoxins on malting barley quality in UK

Abstract

Fusarium head blight (FHB) caused by Fusarium and Microdochium species can significantly affect the yield of barley grain as well as the quality and safety of malt and beer. The present study provides new knowledge on the impacts of the FHB pathogen complex on the malting and brewing quality parameters of naturally infected barley. Quantitative real-time PCR and liquid chromatography double mass spectrometry were used to quantify the predominant FHB pathogens and Fusarium mycotoxins, respectively, in commercially grown UK malting barley samples collected between 2007 and 2011. The predominant Fusarium species identified across the years were F. poae, F. tricinctum and F. avenaceum. Microdochium majus was the predominant Microdochium species in 2007, 2008, 2010 and 2011 whilst Microdochium nivale predominated in 2009. Deoxynivalenol and zearalenone quantified in samples collected between 2007 and 2009 were associated with F. graminearum and F. culmorum, whilst HT-2 and T-2, and nivalenol in samples collected between 2010 and 2011 correlated positively with F. langsethiae and F. poae, respectively. Analysis of the regional distribution and yearly variation in samples from 2010 to 2011 showed significant differences in the composition of the FHB species complex. In most regions (Scotland, the South and North of England) the harvest in 2010 had higher concentrations of Fusarium spp. than in 2011, although no significant difference was observed in the Midlands between the two years. Microdochium DNA was significantly higher in 2011 and in the North of England and Scotland compared to the South or Midlands regions. Pathogens of the FHB complex impacted negatively on grain yield and quality parameters. Thousand grain weight of malting barley was affected significantly by M. nivale and M. majus whilst specific weight correlated negatively with F. avenaceum and F. graminearum. To determine the impact of sub-acute infections of the identified Fusarium and Microdochium species on malting and brewing quality of naturally infected samples, selected malting barley cultivars (Optic, Quench and Tipple) were micromalted and subjected to malt and wort analysis of key quality parameters. F. poae and M. nivale decreased germinative energy and increased water sensitivity of barley. The fungal biomass of F. poae and F. langsethiae correlated with increased wort free amino nitrogen and with decreased extract of malt. DNA of M. nivale correlated with increased malt friability as well as decreased wort filtration volume. The findings of this study indicate that the impact of species such as the newly emerging F. langsethiae, as well as F. poae and the two non-toxigenic Microdochium species should be considered when evaluating the quality of malting barley.

Fusarium poae Pathogenicity and Mycotoxin Accumulation on Selected Wheat and Barley Genotypes at a Single Location in Argentina

“…Deoxynivalenol (DON), commonly produced by F. graminearum, is one of the principal quality problems of malting barley (27). Recently, Nielsen et al (25) demonstrated that F. poae affects malting and brewing parameters, and that F. poae DNA showed a significant positive relationship with NIV. However, specific studies on the effect of NIV on beer are needed.…”

Defensins from the tick Ixodes scapularis are effective against phytopathogenic fungi and the human bacterial pathogen Listeria grayi

“…The ascomycete F. graminearum has major economic impact in the agriculture industry [52]. In general, the control of Fusarium spp has become challenging; for example azole, one of the available fungicides, is only moderately effective against F. graminearum [53].…”

Comparative studies about fungal colonization and deoxynivalenol translocation in barley plants inoculated at the base with Fusarium graminearum, Fusarium culmorum and Fusarium pseudograminearum

“…These pathogens are responsible for quantitative damages, with significant yield losses (Hollaway et al 2013, Nielsen et al 2014 and, in particular when they cause FHB, of qualitative damages, due to mycotoxin accumulation in the grains. In fact, these three Fusarium species are all able to biosynthesize mycotoxins, in particular deoxynivalenol (DON), belonging to the group B of trichothecenes (Bottalico andPerrone 2002, Xu andNicholson 2009).…”

“…The epidemiology of FHB, especially on wheat, is well known Nicholson 2009, Scherm et al 2013) and symptom gravity is often associated with a high proliferation of Fusarium biomass and a significant accumulation of mycotoxins (Pancaldi et al 2010, Nielsen et al 2014. Conversely, for FCR, the relationship between symptom severity, fungal biomass and mycotoxin accumulation is still poorly understood, because Fusarium causal agents do not directly colonize the head.…”

“…Fungi belonging to the genus Fusarium represent unwanted microorganisms for the quality of final malt and beer as well as for beer consumers' health due to mycotoxin contamination related to their presence (Sarlin et al 2005, Wolf-Hall 2007, Christian et al 2011, Oliveira et al 2013, Bertuzzi et al 2011, Hückelhoven et al 2018. Furthermore, one of the main concerns of the malt industry is the gushing phenomenon (Garbe et al 2008), which, as reported by some authors, seems to be influenced by the presence of hydrophobins produced by FHB pathogens (Sarlin et al 2005, Nielsen et al 2014. Despite the issues, there is little in literature on the barley colonization process by Fusarium species compared to the extensive literature concerning wheat.…”