Differential humidity effects on seed viability and oxidative stress responses in Quinoa (Chenopodium Quinoa Willd.)...

This study investigated the effects of relative humidity (RH) and storage duration (SD) on quinoa seed viability, biochemical composition and physiological traits. A factorial experiment in a completely randomized design (CRD) was conducted at 50 °C with two RH levels (30% And 60%) and three storage durations (30, 60, And 90 days). The objective was to evaluate how RH and storage time influence seed viability and identify varietal differences in storage tolerance. Higher RH (60%) accelerated seed viability decline during prolonged storage, as reflected in reduced germination percentage, vigor index, and sharp losses in tetrazolium (TZ) viability, particularly in V5 (91.67% to 9%). Electrical conductivity increased with storage time, indicating membrane damage. Morphological traits (root length, shoot length and biomass) photosynthetic pigments decreased more markedly under 605 RH, with V1 performing poorest and V6 showing relatively better resilience. Antioxidant enzyme (SOD, POD, CAT, APX) were more active under 30% RH, suggesting an adaptive defense response, while proline accumulation was highlighted in V6 (42.73 µmol/g) at 305 RH after 90 days. Overall, prolonged storage under high RH severely compromised quinoa seed quality, whereas 30% RH preserved viability and biochemical integrity. Statistical analyses (ANOVA, PCA and heatmaps) confirmed superior seed performance at 30% RH. These findings provide practical guidance for optimizing quinoa seed storage and highlight V6 as a promising genotype for a long term preservation.