Quinoa (Chenopodium quinoa Will.) is an annual herbaceous Andean plant. In recent years there is a growing interest on it due to its high quality as food, its wide adaptation to agroecological conditions and resistance to different abiotic stresses. In this work, we evaluate the growth pattern of quinoa plants cv. ‘Titicaca’, subjected to different levels of salinity, focusing on leaf production and nutrient content. In this sense, the results have shown that a high concentration of salinity negatively affects the growth of quinoa plants. In fact, plants grown with 200 mM NaCl reduced the photosynthetic rate and levels of chlorophylls and carotenoids in comparison with the rest of the treatments. Likewise, it has been proven how the progressive increase in salinity has negative effects on transpiration, stomatal conductance and photosynthetic rate, with significant subsequent reductions in shoot biomass, leaf area and nutrient adquisition, but without a decline in leaf dry weight (DW) production. However, the treatment of 200 mM NaCl demonstrated the best results regarding the water-use efficiency, as well as the number of saline glands. According to our results, the quinoa plant cv. ‘Titicaca’ seems to be tolerant to moderate concentrations of salinity (50–100 mM NaCl). This study could serve as a reference on this little known and cultivated species in the Mediterranean region, since it could become an alternative crop in areas with moderate salinity problems.
