Submitted to: Symposium Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 7/15/2007
Publication Date: 7/19/2007
Publication URL: http://www.wildflowersymposium.com/
Citation: Walters, C.T. 2007. Longevity of Native Wildflower Seeds. Symposium Proceedings and oral presentation for the Wildflower Symposium. July 19-20, 2007, Orlando, Flordia. Interpretive Summary: This paper will describe the factors that affect seed longevity of wild-collected seeds. We use factors that were developed for domesticated species, which produce highly uniform crops, and add additional considerations for the heterogeneity that is usually found in the wild. Storage relative humidity and temperature are the most important variables and are the most easily controlled.
Technical Abstract: Wildflowers and forbs used for production, plantings and restoration generally exhibit ‘orthodox’ storage behavior, meaning that longevity can be adjusted by balancing storage relative humidity and temperature. An RH of about 20 to 30% at the storage temperature provides optimum moisture conditions for maintaining seed viability. There is no one-protocol-fits-all circumstance, and good moisture control can be achieved using multiple strategies. These strategies must account for the difference between drying and storage temperature and fluctuations of storage temperatures, which are usually gleaned from RH- temperature-seed water content interactions described by water sorption isotherms. The longevities achieved by adjusting RH and temperature vary among species, with some seeds having relatively short life spans (e.g., Allium sp.) and some surviving for extended periods (e.g. Abutilon sp.). Seed aging occurs in two major phases, one that is asymptomatic and one with cataclysmic losses in seed viability. This biphasic kinetic has profound implications on the detection of aging and on genetic changes that occur in the sample during storage.