Establishment of in vitro germination of Distichlis spicata and response to osmotic stress

Distichlis spicata var. stricta (L) Greene is a grass able to grow during drought or flooding seasons, as well as in poor, saline, and alkaline soils, making it an ideal model system to study salinity and water stress tolerance in plants. However, it is known to have an extremely low germination rate in the field, as low as 3%. Here, we established in vitro conditions to study the factors that affect D. spicata under osmotic and salt stress. Treatments that included mechanical scarification, 4°C stratification, and 20% NaDCC (w/v) disinfection significantly increased the germination rate up to 84% in only 5 days. Furthermore, saltgrass had good seed germination under high salinity (ionic) stress caused by 150 and 200 mM NaCl (50% and 30%, respectively). Saltgrass was sensitive to osmotic agents Mannitol and Sorbitol during the germination stage, suggesting that this is a main limiting developmental stage for D. spicata success under osmotic environments.