Evaluation of quinoa seed germination variability in response to temperature,, drought and salinity stresses

Quinoa has attracted a lot of attention in recent years due to its low ecological needs and rich nutritional value. Therefore, the variability of germination components to temperature and determination of cardinal temperatures were performed by seed germination test at different constant temperatures from -1 to 45°C.The results of the dent-like model showed that the base temperature and ceiling temperature of quinoa were -03.04 and 45.45°C, respectively, and the optimum temperature was from 20 to 35°C. To investigation the effect of salinity and drought stress on germination at 25°C, the seeds were exposed to osmotic potentials from 0 to -28 bar, which were made of sodium chloride (NaCl) and polyethylene glycol (PEG), respectively, to induce stresses. The results showed that the reduction of osmotic potential up to -12 bar was not able to significantly reduce the germination components compared to normal conditions. However, with decreasing osmotic potential to -18 and -24 bar, the germination percentage decreased significantly. The germination was completely stopped at -24 bar of drought-induced, while 24% germination was observed at the same point of the salinity-induced osmotic potential. Therefore, seed germination capacity under salinity-induced stress was more tolerant than drought-induced stress at all levels of osmotic potentials. Most likely, due to the fact that quinoa is halophyte, by absorbing the ionic elements of salt, required for the maintenance of the cell turgor, which concurrent increase in cytosolic osmolality. Thus, this species has a great potential for distribution to other areas such as provinces with dry climate.