Hormonal Control of Germination under Saline Conditions of Three Halophytic Taxa in the Genus Suaeda

The interaction between hormones and salinity on seed germination of three halophytic taxa in the genus Suaeda: S. maritima (L.) Dum. var. flexilis Focke and var. macrocarpa Moq., and S. depressa (Pursh) Wats, was studied. Exogenous applications of kinetin and gibberellic acid (GA3) were applied in order to determine if either of these growth‐promoting hormones would promote germination in the two dormant taxa, Suaeda depressa and S. maritima var. flexilis and to see if osmotically induced dormancy by NaCl could be alleviated. Our results indicate that gibberellic acid is capable of breaking dormancy in these species with dormant seeds, but kinetin proved to be ineffective. A seed dormancy that was induced by osmotic stress could also be alleviated by treatments with gibberellic acid. Endogenous concentrations of both cytokinins and gibberellins were measured in seeds exposed to osmotic stress (0.85 M NaCl), and we found a reduction in cytokinin activity in these three taxa. Gibberellin‐like activity was reduced in S. depressa when seeds were soaked in 0.85 M NaCl.