Salinity tolerance mechanisms during germination and early seedling growth in Chenopodium quinoa Wild. genotypes with different sensitivity to saline stress

•Salt stress tolerance mechanisms during germination in different C. quinoa genotypes were investigated.•Among genotypes, CICA was the most tolerant while Chadmo the most sensitive to salt-stress.•Saline stress induced a greater stimulation of the activity of most of the antioxidant enzymes in Chadmo than in CICA.•In the presence of salt, CICA embryos increased Na+/K+ ratio but maintained Na+/Ca2+ levels when compared to Chadmo•Down-regulation of betalains content in CICA seedlings impaired normal germination under salt-stress.