Combined effects of saline irrigation and genotype on the growth, grain yield and mineral concentration of durum wheat in hot arid areas

Abstract

Durum wheat cultivation in many parts of the Middle East is viable only under irrigation, often with saline water. This study evaluated the effects of salinity, season, and genotype on durum wheat grain yield and quality. Ten durum wheat genotypes were grown for two consecutive seasons under different irrigation salinities (2.6, 10, and 15 dSm⁻¹) in sandy soils at the International Center for Biosaline Agriculture (Dubai, UAE). Various traits were evaluated, including grain yield (GY), biomass, plant height, number of spikes per plant, thousand grain weight (TGW), chlorophyll content, and grain isotope composition. Salinity reduced GY, agronomic traits, and chlorophyll content, while increasing δ¹³C and sodium (Na) concentration in grains. The season effect significantly impacted GY, biomass, TGW, and some mineral concentrations, potentially due to heat waves during grain filling. The genotypic effect was significant for GY, agronomic traits, and concentrations of nitrogen and most minerals. A negative phenotypic correlation was found between GY and both Na and δ¹³C, suggesting that better water status and lower Na accumulation were linked to genotypes with improved performance. However, there was no negative trade-off across genotypes between grain yield and concentrations of most minerals. Moreover, the accumulation of N and several nutrients (P, Mg, Mn, Fe, Zn, Cu, S) in grains followed a similar pattern, with positive correlations observed. We conclude that genotypic variability is crucial to improving yield and modulating mineral content in durum wheat grown under saline irrigation in hot arid areas.