|DILL-MACKY, RUTH - University Of Minnesota|
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 12/5/2017
Publication Date: N/A
Technical Abstract: Manipulating the microbiome of wheat seeds and heads may contribute to control of Fusarium head blight and mycotoxin accumulation in grain, which creates a food safety hazard. With the aim of identifying novel management targets, we looked for correlations between Fusarium biomass or deoxynivalenol (DON) content and characteristics of the microbial communities inhabiting wheat grain. Individual seeds were sampled in an attempt to approach the fine spatial scale at which microbial communities are organized. Seeds were collected from a common wheat variety planted across a mist irrigated nursery in St. Paul, Minnesota, in each of two successive years. Across 96 seeds in 2016, DON content varied by c. 470 fold (from 5.4 to 2517 µg DON g-1 seed), and Fusarium biomass varied over 1 million fold (from 1.9X100 to 2.3X106 copies TRI5 mg-1 seed). The relationship between Fusarium biomass and DON content was strong (for log transformed values; adjusted R2=0.63, P<0.001). However, fit with DON content was improved in an additive model including both Fusarium biomass and bacterial diversity (Hills index; adjusted R2=0.82, PHills<0.001). Similarly, additive models including the relative abundance of particular bacterial taxa sometimes improved fit with DON content, compared to the model including Fusarium biomass alone. For the samples presenting the greatest deviation from the expected relationship between Fusarium biomass and DON content, bacterial communities could be readily distinguished between seeds with lower vs. higher than expected DON content. These data suggest that bacterial communities associated with wheat seeds may substantially impact the development of Fusarium head blight and the accumulation of mycotoxins in grain. With rigorous development, the microbiome of wheat heads may become a target for agricultural management.