Physiological and biochemical markers for screening salt tolerant quinoa genotypes at early seedling stage

The present study was conducted to determine the predictive screening parameters of quinoa salt tolerance that can be applied at early development stages, based on physiological and biochemical approaches. Four quinoa varieties (Tumeko, Red Faro, Kcoito and UDEC-5) were cultivated using hydroponic system, and treated for 2 weeks with different NaCl concentrations (0, 100, 300 and 500 mM). Salt treatment induced a decrease of plant growth depending on NaCl concentrations, plant organs and varieties. Red Faro and UDEC-5 exhibited low level of Na+ accumulation and high K/Na selectivity. UDEC-5 showed high stomatal conductance leading to high net photosynthesis, even at 500 mM NaCl. Red Faro and UDEC-5 exhibited low level of lipid peroxidation, high antioxidant activities and high proline accumulation, as an indicator of ROS defense and osmotic adjustment. This study suggested that these physiological and biochemical traits could be used as screening criteria for selecting salt tolerant genotype.