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Poster: Biology & Disease Mgmt: Integrated Pest Mgmt


Deciphering soil and plant microbiomes associated with suppression of soybean diseases
H. PFAFFE (1), S. Marzano (1), L. Domier (1), A. Davis (1), D. Eastburn (1) (1) University of Illinois, U.S.A.

General disease suppression of soilborne pathogens can add to the toolbox of strategies for disease management. This study was undertaken to identify the microbiome indicators for soil suppressiveness to sudden death syndrome (SDS) of soybeans. Five cover crop treatments (rye, vetch, mustard, rye+vetch, fallow) and two tillage methods (chisel plow, ridge till) were compared. Each cover crop plot was divided to receive both tillage treatments, and there were four replications of this experiment. Soybean plants were evaluated for naturally occurring foliar and root diseases at the R6-R7 growth stage. Root, rhizospheric soil, and bulk soil samples were taken early in the season, and DNA was extracted for PCR amplification, targeting 16s bacteria and archaeal, and ITS genes, for subsequent high throughput sequencing. Our results have shown no significant differences in microbial populations of the cover crop treatments. However, there are several notable differences with the tillage treatments. Chisel plowed plots had increased levels of the genera, Verrucomicrobia, Glomeromycota, Proteobacteria, and Actinobacteria. Ridge tilled plots showed increased levels of Streptophyta, Firmicutes, and Crenarchaeota. These results are being verified with a greenhouse assay to determine if it is possible to delineate microbiome profiles that correspond to general disease suppression.