Biochemical Characterization and Responses of Two Contrasting Genotypes of Chenopodium quinoa Willd. to Salinity in a Hydroponic System

Abstract

Chenopodium quinoa is a promising species for future food security and combating climate change due to its nutritional content and halophytic nature. This study focuses on the temporal differential responses of the salt-tolerant (Chadmo) and the salt-sensitive (Kankolla) under control (CK) and 400 mM NaCl arranged under the randomised block designed (RBD). Biochemical features assessed and results indicate a significant difference (p<0.05) being identified by ANOVA and Tukey analyses in total chlorophyll (CHL), carotenoids (CAR), proline, glycine betaine (GB),  soluble sugars,  K+, Na+, K+/Na+ ratio, Mg2+ and Ca2+ in both genotypes between the CK and 400 mM NaCl. Na+ increased while K+ and the bivalent ions Mg2+ and Ca2+ decreased progressively with time points (CK and 24 h) in both genotypes but more pronounced in Kankolla. Proline increased by 24.45 and 18.63% between the CK and 24 h after exposure to 400 mM NaCl in Chadmo and Kankolla, respectively. Similarly, significant increases were observed in ABA, glycine betaine and soluble sugars from the CK to 24 h after exposure to 400 mM NaCl in both genotypes. Using these biochemical responses to salinity, Chadmo proved to be the better-performing genotype when exposed to 400 mM NaCl and hence identified as the salt-tolerant genotype.