Soil sodicity is more detrimental than salinity for quinoa (Chenopodium quinoaWilld.): A multivariate comparison of physiological, biochemical and nutritional quality attributes

Soil salinization is a serious environmental problem worldwide. To explore the comparative effects of soil salinity and sodicity on physiological, biochemical and nutritional quality attributes of four quinoa genotypes (A1, A7, Puno, Vikinga), pot and field experiments were performed on non-saline soil and two types of salt-affected soils designated as SS1 (saline) and SS2 (saline-sodic). The results of both the experiments showed similar reduction pattern in biomass (11%-44%), chlorophyll content (10%-36%), stomatal conductance (18%-32%) and grain yield (30%-47%) of four genotypes on SS2 compared with SS1. Higher sodicity level of SS2 resulted in more Na accumulation (23%-40%) and oxidative damage (12%-35% decrease in membrane stability) leading to an increase in the activities of antioxidant enzymes (SOD, POD, CAT) in all the genotypes. Grain mineral contents (except Na and Mg) were decreased more in SS2 than SS1. Multivariate analysis revealed that grain Na content has negative correlation with all the nutritional quality attributes except Mg and fibre contents. Genotypes A1 and A7 were more salt tolerant with better grain nutritional quality than Puno and Vikinga. It is concluded that soil sodicity is more detrimental than salinity, and quinoa genotypes A1 and A7 are better than Puno and Vikinga for cultivation on saline and saline-sodic soils.