Effects of salt stress on tolerant accessions of quinoa at the morphological and metabolic levels

Quinoa (Chenopodium quinoa Willd.) is a facultative halophyte recognized for its genetic variability and high tolerance to salinity. The objective of this study was to evaluate the effect of NaCl on three accessions of quinoa from the Camacani germplasm bank of the National University of the Altiplano, Peru, at three NaCl concentrations (0, 200 and 400 mM) under greenhouse conditions. Four morphological variables (plant height, root length, percentage of root DM, and aerial DM), as well as seven metabolic variables (chlorophyll, proline, phenols, flavonoids, saponins, amino acids and proteins content by spectrophotometric analysis) and electrolyte leakage (EL) in leaves were analyzed. Increasing NaCl exposure was positively correlated with increases in EL, proline, and saponin, while negatively correlated with leaf protein content. In accession PECQ 20037, for example, foliar protein content varied from 18.7% at 0 mM NaCl to 10.57% at 400 mM NaCl. The results indicated that accessions PECQ 20037 and Negra Oruro tolerated the 400 mM NaCl concentration better than Sajama.