CATION CONCENTRATION IN POST-IMBIBED WINTERFAT SEEDS AS INFLUENCED BYIMBIBITION TEMPERATURE

Winterfat [Eurotia lanata (Pursh) Moq.] is a chenopod shrub often used in range seedings because of its palatability and nutritive value. En vironmental conditions influence winterfat germination and seedling vi gor and, therefore, seedling success. We tested the hypothesis that se ed imbibition at warm temperatures damages seed membranes, resulting i n lower post-imbibition concentrations of seed cations. Energy-dispers ive x-ray microanalysis of Cl uptake and fresh weight increase over ti me gave evidence that winterfat seeds imbibe more rapidly at 25 than a t 4-degrees-C. However, imbibition of seeds at 20-degrees-C did not re sult in consistently lower post-imbibition cation concentrations. Alth ough imbibition is more rapid at warm temperatures, the post-imbibitio n concentration of cations in seeds imbibed at 20-degrees-C does not j ustify the conclusion that warm imbibition damages winterfat seed memb ranes.