Anatomical and physiological responses of four quinoa cultivars to salinity at seedling stage

Abstract

Premise of research. Salinity constitutes a stress factor that limits plants growth and development. It is known that salinity shows most damaging effects on plant development during the seedling stage. Therefore, comparison of salt tolerance among cultivars/varieties of crop species at seedling stage constitutes a very important topic to agricultural sustainability. Methodology. In this work, anatomical and physiological features of cotyledons and roots of four quinoa (Chenopodium quinoa) cultivars subjected to saline stress were analyzed. Pivotal results. There were no visible symptoms associated to salt damage. But several changes at both tissular and cellular organization levels were observed. Anatomical attributes of cotyledons (e.g. adaxial and abaxial stomatal area and density, palisade and spongy cell layers, and palisade cell density) and roots (root length and diameter, stele diameter and surface, and metaxylem vessel diameter) were differently affected by saline treatment among quinoa cultivars. Accumulation of compatible osmolites i.e. soluble sugars and proline showed different patterns in both cotyledons and roots of salt-treated seedlings. Conclusions. Anatomical and physiological results of this study permit establish that different strategies to face saline stress occurring at different combinations among quinoa cultivars, but conferring a similar fitness to cope salt toxicity and also survive under extreme conditions.