Comparison of Salt Stress Tolerance among Two Leaf and Six Grain Cultivars of Amaranthus cruentus L.

Abstract

Amaranths (Amaranthus L.) are multi-use crop species renowned for their nutritional quality and their tolerance to biotic and abiotic stresses. Since the soil salinity of croplands is a growing problem worldwide, we tested the salinity tolerance of six grain and two leaf cultivars of Amaranthus cruentus L. The plants were grown for 53 days under hydroponic conditions at 0, 50 and 100 mM NaCl. We investigated the growth rate, photosynthetic activity, mineral content, pigments and biochemical compounds involved in oxidative stress. Although 100 mM NaCl always decreased biomass production, we highlighted Don Leon and K91 as tolerant cultivars under moderate salt stress (50 mM NaCl). Under salinity, sodium accumulated more in the shoots than in the roots, particularly in the stems. Sodium accumulation in the plants decreased the net photosynthetic rate, transpiration rate and stomatal conductance but increased water use efficiency, and it decreased chlorophyll, betalain and polyphenol content in the leaves. It also decreased the foliar content of calcium, magnesium and potassium but not the iron and zinc content. The physiological parameters responded differently to sodium accumulation depending on the cultivar, suggesting a different relative importance of ionic and osmotic phases of salt stress among cultivars. Our results allowed us to identify the morpho-physiological traits of the cultivars with different salt tolerance levels.

Salt Stress Induces Contrasting Physiological and Biochemical Effects on Four Elite Date Palm Cultivars (Phoenix dactylifera L.) from Southeast Morocco

“…The PCA successfully distinguished the salt-sensitive cultivars from the other cultivars, thereby validating the findings reported by [ 66 ]. Specifically, the PCA effectively separated the salt stress-tolerant cultivars from the sensitive ones, mainly along the PC1 axis, which contained the highest amount of information (77.69%) ( Figure 9 ).…”

“…Principal component analysis (PCA) is a widely utilized multivariate method employed for classification purposes, enabling the discrimination of samples based on their diverse biological status, origin, or quality. This approach has been extensively documented in the literature [ 65 , 66 ]. In this study, the combination of PCA and membership function value (MFV) was employed to classify the four cultivars into distinct groups, based on various morphophysiological and biochemical parameters, with the aim of discerning their level of salt tolerance.…”