Seed-associated microbes of an intermediate species, Zizania palustris , in submerged storage and the impact of anti-microbial seed treatments

Northern Wild Rice (NWR; Zizania palustris ) is an ecologically important, annual, aquatic species native to North America that is also cultivated in irrigated paddies. NWR seeds are desiccation-sensitive and commonly stored submerged in water, where viability can rapidly decline post-dormancy break. During this short time period, microbial growth can be rampant. However, little is known about the impact of microbial communities on NWR seeds in storage. In this study, we evaluated the efficacy of four antimicrobial treatments at reducing microbial growth in submerged NWR seed storage, quantified by the culturable microbiome, and the impact on seed germination after the storage period. While the treatments did not impact seed germination significantly, we identified shifts in the microbial communities between the control and antimicrobial treatments. In general, fungi were more predominantly found in the control, while bacteria were more predominantly found in treatments, suggesting that bleach and H 2 O 2 reduced the recovery of culturable fungi. Proteobacteria, Pseudomonas and Sphingomonas , were major constituents of the NWR seed microbiome as were genera with species known to be pathogenic to NWR including Fusarium and Xanthomonas . Overall, this study provides a first look at the NWR seed microbiome during submerged storage and a foundation for future studies to evaluate the effect of microbial communities on NWR seed viability during submerged storage.