Salinity and drought tolerance in Suaeda vermiculata, A habitat indifferent halophyte of the hyper-arid deserts of the united arab emirates (UAE)

The results showed that drought tolerance was higher for seeds of the non-saline than those of saline habitat and this tolerance was more obvious at higher temperatures. Seeds of the saline habitat germinated in lower osmotic potentials (-0.8 and -1.0 MPa) only at lower temperatures, but those of the non-saline habitat germinated to higher levels at all higher temperatures. Germination rate index was significantly greater in seeds of non-saline at lower osmotic potentials. Most seeds that failed to germinate in the different PEG concentrations recovered their germination when transferred to distilled water. Seeds from both saline and non-saline habitats were germinated in different levels of salinity (0 to 500 mM NaCl) in both light and darkness at three different temperatures (15/25 °C, 20/30 and 25/35 °C). The overall germination was significantly greater for seeds of non-saline, compared to that of saline habitat. In addition, light germination was significantly

Few halophytes can grow well in both saline and non-saline habitats (i.e., habitat- indifferent). These plants offer a good opportunity to assess maternal salinity on drought and salinity tolerances during germination. Habitat-indifferent halophyte Suaeda vermiculata (Amaranthaceae) in a desert ecosystem of the United Arab Emirates (UAE) was assessed in this PhD Memory. Here, we assessed the effects of maternal salinity, drought as simulated with PEG (Polyethylene glycol), and light and temperature of incubation and their interactions on germination. In addition to, the effects of maternal salinity, temperature, and light of seed incubation on seed dormancy and salinity tolerance during the seed germination stage. Furthermore, determine the maternal salinity on some plant physiological and biochemical traits on different organs of S. vermiculata from salty and non-salty habitats. Matured seeds of S. vermiculata in saline and non-saline soils were germinated in six PEG concentrations (0 to -1.0 MPa) and in different levels of salinity (0 to 500 mM NaCl) with incubation in different temperatures in both light and dark regimes. Studied germination attributes were final germination, germination rate index (GRI) and germination recovery of non-germinated seeds when transferred to distilled water. Furthermore, samples of different organs were collected from both habitats. Physiological and bio-chemical features (chlorophyll and carotenoids, proline, malondialdehyde (MDA), and hydrogen peroxide (H2O2), antioxidant enzymes (Catalase, CAT; guaiacol peroxidase, GPX; Ascorbate peroxidase, APX) activities) were assessed. Elemental compositions in soil and plant samples from both habitats were also assessed.