Seedbed ecology of winterfat: cations in diaspore bracts in their effect on germination and early plant growth

Abstract

The concentrations of Ca++, Mg++, K+, and Na+ in seeds and bracts of winterfat [Eurotia lanata (Pursh) Moq.] diaspores were studied using atomic absorption spectrophotometry. The concentration of Ca++ in the bracts was about 9 times that of seed concentrations. Bract and seed concentrations for the other cations were more equal. All cation concentrations were highly variable. Analyses of seed for cation concentrations before and after diaspore imbibition, and after seed imbibition in prepared cation solutions, revealed significant imbibitional increases in seed-cation concentrations. Increases in seed Ca++ or Na+ improved moisture absorption and germination by the seed, and hypocotyl elongation in the seedling. It is concluded that diaspore bracts are a source of nutrients for the winterfat seed and that these inorganic nutrients are a positive factor in plant establishment.