Biology subjects

Kimball, J.

Publications and source records attributed to Kimball, J..

2 recordsLinked to original sources

bioRxiv2021

Dormancy Breaking Treatments in Northern Wild Rice (Zizania palustris L.) Seed Suggest a Physiological Source of Dormancy

Dormancy is a limiting factor for breeding in northern wild rice (NWR; Zizania palustris L). This study developed a dormancy curve and tested a combination of scarification and hormone treatments, across three timepoints, for their ability to break dormancy in NWR and produce viable seedlings and plants. A dormancy curve was established across 9 months post-harvest, which showed maximum germination (95%) by 17 weeks post-harvest and high germination ([≥]81 %) through the rest of the testing period. Next, dormancy breaking treatments were tested. At 1 week post-harvest, few seeds germinated ([≤] 15 %) across all treatment combinations. However, sulfuric acid increased germination shortly after harvest (5.8 %), compared to water (0.5 %) and NaClO (0 %) but resulted in stunted seedlings, all but one of which died shortly thereafter. At 7 weeks, sulfuric acid treated seeds did not result in significantly higher germination than water and maximum germination was still below 15%. By 11 weeks post-harvest, the water treatments had the highest germination and resulted in the most viable plants, indicating that dormancy had begun to break naturally and exceeded the effect of the other scarification treatments. Hormonal treatments had no significant effect on germination or seed viability and no strong conclusions could be drawn about their effect on seedling or plant health. Due to the inability of early germinated seed to consistently produce viable plants and the increase in germination following sufficient cold storage, it is likely that NWR seed has intermediate or deep physiological dormancy.

plant biology↗

bioRxiv2021

Evaluation of a Recessive Male Floret Color in Cultivated Northern Wild Rice (Zizania palustris L.) for Pollen-Mediated Gene Flow Studies

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.

plant biology↗