Adaptive drought tolerance during germination of Salsola drummondii seeds from saline and non-saline habitats of the Arid Arabian Deserts

The effects of temperature, light, salinity, and drought on germination of halophytes have been extensively studied. However, few studies have focused on the germination of plants that grow well in both saline and non-saline habitats (i.e., habitat-indifferent halophytes). Here, we assess the impacts of population origin, temperature, and light on drought tolerance, as simulated by polyethylene glycol (PEG), during germination of Salsola drummondii, a habitat-indifferent halophyte from the arid Arabian deserts. Seeds were collected from both saline and non-saline habitats and germinated at six PEG levels at three temperatures and two light regimes. An increase in PEG concentration resulted in a significant reduction in seed germination, especially at higher temperatures. Seeds from the non-saline habitat attained significantly greater germination efficiency at PEG levels up to -1.2 MPa, but there was no difference in germination of seeds between the two habitats at -1.5 MPa PEG concentrations. Saline habitat seeds germinated significantly faster at higher PEG levels. Germination was significantly higher in dark than in light at -1.5 MPa at lower temperatures, but the opposite was true at higher temperatures. Seeds from saline habitats had higher dormancy and faster germination at higher concentrations of PEG due to adaptation to low osmotic potentials.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author