Tuesday, November 6, 2007
152-2
Environmental Factors Determining Phenolic Compound Composition in Wild Oat (Avena fatua): Consequences for Seed Bank Dynamics.
Kristen Granger1, Robert Gallagher2, E. Patrick Fuerst3, Ann Kennedy4, Rich Alldredge5, Amanda Snyder3, Doug Pittman6, James Anderson7, and Wendy McCoy8. (1) Penn State University, 116 ASI Bldg, University Park, PA 16803, (2) 116 ASI Building, Penn State University, Penn State University, Dept. of Crop & Soil Sciences, University Park, PA 16802, (3) Washington State University, E202 Food Quality Building, P.O. Box 646394, Pullman, WA 99164-6394, (4) USDA-ARS, WSU USDA-ARS, 217 Johnson HallPO Box 646421, Pullman, WA 99164-6421, (5) Statistics, Washington State University, Neill 401, Pullman, WA 99164-3144, (6) Department of Crop and Soil Sciences, Washington State University, Pullman, WA 99164-6420, (7) USDA-ARS Fargo, 1605 Albrecht Blvd., P.O. Box 5674, Fargo, ND 58105-5674, (8) Crop and Soil Sciences, Pennsylvania State University, 116 ASI, Pennsylvania State University, University Park, PA 16802
Weed seeds can persistence in the soil seed bank for many years, creating long-term management issues for farmers. This persistence has been attributed to seed dormancy and other factors that enable retention of seed vigor and resistance to microbial decay. Phenolic compounds in the seeds have been linked to seed dormancy, vigor and resistance to decay. In our research, we hypothesize that stress during weed seed development and maturation will reduce the allocation of these chemicals in seeds and thereby reduce seed persistence in the seed bank. Using Avena fatua (wild oat) as a model species, plants were grown under drought, shade, and nitrogen limitation. Seeds from these plants were evaluated for seed phenolics, dormancy, vigor, and resistance to decay. Preliminary data suggests that drought results in seeds that are less dormant and lower levels of total phenolic compounds than seeds from non-stressed environments. Further data will be presented on the implications of the other stress factors on seed quality and subsequent plant fitness. These data will be used to determine management thresholds that provide adequate weed control while minimizing off-site environmental impacts and selection pressure for herbicide resistance.