Northern wild rice (NWR; Zizania palustris L.) is a wind‐pollinated, annual, aquatic grass that grows naturally in the Great Lakes region of the United States and Canada and is also cultivated in flooded paddies, predominantly in California and Minnesota. A better understanding of pollen‐mediated gene flow is needed within the species for both conservation and breeding efforts as cultivation occurs within the species’ natural range and spatially‐isolated, paddy structures are limited within breeding programs. Widely‐cited pollen travel research in NWR demonstrated that pollen could travel at least 3200 m. However, a population segregating for male sterility was used as the pollen recipient in the study and was determined to not be adequate for NWR pollen travel studies. Here, we present the characterization of a recessive white male floret (WMF) population in contrast to the dominant, purple male floret (PMF) color of cultivated NWR along with estimates of pollen‐mediated gene flow in a cultivated paddy setting. Studies conducted in 2018 and 2019 revealed that the primary amount of pollen‐mediated gene flow occurred within the first 7 m from the PMF donor source with no gene flow detected past 63 m. These results suggest that the likelihood of pollen‐mediated gene flow between cultivated NWR and natural stands remains low. We also identified a strong linkage between male floret, collar, and culm color. This study demonstrates that the WMF trait is an excellent candidate for use in pollen‐mediated gene flow studies in NWR.

Northern wild rice (NWR; Zizania palustris L.) is a wind-pollinated, annual, aquatic grass that grows naturally in the Great Lakes Region (GLR) of the United States and Canada, and is also cultivated in flooded paddies, predominantly in California and Minnesota. A better understanding of pollen-mediated gene flow is needed within the species for both conservation and breeding efforts as cultivation occurs within the species natural range and spatially-isolated, paddy structures are limited within breeding programs. Widely cited pollen travel research in NWR demonstrated that pollen could travel at least 3200m. However, a population segregating for male sterility was used as the pollen recipient in the study and was determined to not be adequate for NWR pollen travel studies. Here, we present the characterization of a recessive white male floret (WMF) population in contrast to the dominant, purple male floret (PMF) color of cultivated NWR along with estimates of pollen-mediated gene flow in a cultivated paddy setting. Studies conducted in 2018 and 2019 revealed that the primary amount of pollen-mediated gene flow occurred within the first 7m from the PMF donor source with no gene flow detected past 63m. These results suggest that the likelihood of pollen-mediated gene flow between cultivated NWR and natural stands remains low. We also identified a strong linkage between male floret, auricle, and culm color. This study demonstrates that the WMF trait is an excellent candidate for use in pollen-mediated gene flow studies in NWR.

Northern wild rice (NWR; Zizania palustris var. interior) (NWR) is an ecologically important, annual, aquatic species native to North America, that is also cultivated in irrigated paddies in Minnesota and California. NWR seeds are desiccation-sensitive and must be kept in hydrated conditions, in which viability can decline rapidly within the first two years of storage. During this period, microbial growth is rampant and the relationship between these communities and the viability of NWR seed is unclear. In this study, we cultured and identified bacteria and fungi found in 27 NWR seed stocks, collected over a five-year period from three locations and four NWR genotypes. Results revealed that microbial communities were heavily dependent on seed viability and communities began shifting after one year of seed storage. Fungi became more prominent as years in storage increased suggesting that fungi begin to outcompete bacteria. Spatial analysis of locations and genotypes revealed a core set of microbes found across locations and genotypes. Penicillium and Pseudomonas were ubiquitous in NWR hydrated seed storage. We also evaluated the efficacy of four antimicrobial treatments at reducing microbial growth in hydrated NWR seed storage. These treatments did not reduce or drastically change microbial growth or seed viability. However, previously undetected microbes were identified after treatments, which suggested a disruption to the major constituents of the microbiome. Overall, this study identified common microbial constituents found in an aquatic, recalcitrant species, adapted for a cold climate, during seed storage and provides a foundation for future studies to evaluate the effect of microbial communities on NWR seed viability during hydrated storage.