Effects of salinity stress on seedling biomass, physiochemical properties and grain yield in different breeding wheat genotypes

Abstract

The salinity tolerance of 17 breeding wheat genotypes along with three local varieties was evaluated under control and salinity stress (160 mM NaCl) conditions. At the seedling stage, shoot and root dry weights, relative water content (RWC), membrane stability index (MSI), relative chlorophyll content (SPAD index), root and shoot Na+ (RN and SN), root and shoot K+ (RK and SK), root and shoot K+/Na+ ratios (RKN and SKN), root-to-shoot Na+ translocation (RTSN), root-to-shoot K+ translocation (RTSK), stomatal conductance (GS), transpiration rate (TE), and photosynthesis rate (PN) were measured. Moreover, the investigated genotypes were assessed in terms of grain yield across four saline regions during the 2018–2019 cropping seasons. Salinity stress caused a significant reduction in the RDW, SDW, PN, GS, TE, SK, RKN, SKN, RTSN, and RTSK, but resulted in increased RN, RK, and SN. The results of AMMI analysis of variance also indicated significant differences among test locations, genotypes, and their interaction effects. The PCA-based biplot revealed that grain yield strongly correlated with RKN and RK. Furthermore, the correlation among PN, GS, and TE traits was strong and positive and had a positive correlation with RWC, MSI, RDW, and SPAD index. Considering our results, RK and RKN were identified as useful physiological tools to screen salt tolerance at the early-growth stage. According to the ranking patterns obtained by the average sum of ranks method (ASR) and grain yield, we observed that genotype number G5 had considerable physiological potential at the early-growth stage and also responded well to soil salinity at the farm; thus this genotype can be promoted for commercial production.