Responses of wheat genotypes to zinc fertilization under saline soil conditions

A greenhouse experiment with four bread wheat [Triticum aestivum L.] genotypes, 'Rushan,' 'Kavir,' 'Cross,' and 'Falat,' and a durum wheat [Triticum durum L.] genotype, 'Dur-3,' at two zinc (Zn) rates (0 and 15 mg Zn kg(-1) dry soil) and four salinity levels (0, 60, 120, and 180 mM NaCl) was conducted. After 45 d of growth, the shoots were harvested, and Zn, iron (Fe), potassium (K), sodium (Na), and cadmium (Cd) concentrations were determined. In the absence of added Zn, visual Zn deficiency symptoms were observed to be more severe in 'Dur-3' and 'Kavir' than in other genotypes. The effect of Zn deficiency on shoot dry matter was similar to its effect on visual deficiency symptoms, such that shoot growth was most depressed in 'Kavir' and 'Dur-3.' At the 180 mM treatment, Zn fertilization had no effect on shoot dry matter of genotypes. Genotypes with high Zn efficiency had greater shoot Zn content than genotypes with low Zn efficiency. In the absence of added Zn, the Dur-3, and 'Cross' genotypes had the highest and lowest Cd concentrations, respectively. Application of Zn had a positive effect on salt tolerance of plants.