Isolates of Fusarium graminearum collected 40–320 meters above ground level cause Fusarium head blight in wheat and produce trichothecene mycotoxins

Abstract

The aerobiology of fungi in the genus Fusarium is poorly understood. Many species of Fusarium are important pathogens of plants and animals and some produce dangerous secondary metabolites known as mycotoxins. In 2006 and 2007, autonomous unmanned aerial vehicles (UAVs) were used to collect Fusarium 40-320 m above the ground at the Kentland Farm in Blacksburg, Virginia. Eleven single-spored isolates of Fusarium graminearum (sexual stage Gibberella zeae) collected with autonomous UAVs during fall, winter, spring, and summer months caused Fusarium head blight on a susceptible cultivar of spring wheat. Trichothecene genotypes were determined for all 11 of the isolates; nine isolates were DON/15ADON, one isolate was DON/3ADON, and one isolate was NIV. All of the isolates produced trichothecene mycotoxins in planta consistent with their trichothecene genotypes. To our knowledge, this is the first report of a NIV isolate of F. graminearum in Virginia, and DON/3ADON genotypes are rare in populations of the fungus recovered from infected wheat plants in the eastern United States. Our data are considered in the context of a new aerobiological framework based on atmospheric transport barriers, which are Lagrangian coherent structures present in the mesoscale atmospheric flow. This framework aims to improve our understanding of population shifts of F. graminearum and develop new paradigms that may link field and atmospheric populations of toxigenic Fusarium spp. in the future.

Genetic and phenotypic diversity within the Fusarium graminearum species complex in Norway

“…Infected seeds represent a risk for introducing pathogens into new areas, and imported seed lots may have introduced 15-ADON into Norway. In addition, long distance dispersal of viable F. graminearum spores is possible (MaldonadoRamirez et al 2005;Schmale et al 2012). We speculate whether the increased prevalence of FGSC observed in several European countries (Chandelier et al 2011;Jennings et al 2004;Stępień et al 2008;Waalwijk et al 2003) including the Nordic countries (Bernhoft et al 2010;Fredlund et al 2008;Nielsen et al 2011;YliMattila 2010) may have facilitated the introduction of the 15-DON genotypes into new areas like Norway and Denmark.…”

Characterization of Fusarium Strains Recovered From Wheat With Symptoms of Head Blight in Kentucky

“…The prevalent chemotype is 15-ADON (14,27,62), which dominates worldwide on wheat in temperate zones (59). Recently, an increase in the representation of 3-ADON isolates in the population has been documented in Canada (11,17,61), the upper Midwestern U.S. (14), and the eastern U.S., from North Carolina to New York (25,47,48). It has been reported that these 3-ADON isolates represent a novel, and likely introduced population.…”

Experimental validation of a long-distance transport model for plant pathogens: Application to Fusarium graminearum

“…tritici, causal agent of wheat stem rust (Stokstad, 2007), are two pathogens of recent concern that disperse their spores via the atmosphere (Krupa et al, 2006;Livingston et al, 2004;Pan et al, 2006;Singh et al, 2006Singh et al, , 2008aStokstad, 2007). Fusarium graminearum is another fungal plant pathogen that utilizes the atmosphere for spore transport (Maldonado-Ramirez et al, 2005;Schmale et al, 2006Schmale et al, , 2012. This fungus is responsible for Fusarium head blight (FHB) of wheat and barley, which has resulted in more than $3 billion in crop losses in the United States over the past couple of decades (McMullen et al, 1997;Paulitz, 1999;Schmale III and Bergstrom, 2003).…”