The Effect of Absorbable Zinc Deficiency on some Physiological and Morphological Traits in Bread Wheat

Zinc is one of the most critical nutrient elements limiting the plant growth. To investigate the effects of soil Zn deficiency on some physiological and morphological traits in bread wheat (Triticum aestivum L.), a factorial experiment was conducted based on completely randomized design (CRD) with three replications in greenhouse. Zn-efficient (Bayat and Nik-nejhad) and inefficient (Hirmand and Karaj-1) cultivars were grown in Zn-deficit (0 mg kg-1 soil) and -adequate (5 mg kg-1 soil) soils. The studied traits were 1000 grain weight, number of grains per spike, chlorophyll content, grain, root and leaf Zn concentrations and some morphological traits. The results of variance analysis showed that all traits are significantly (P≤0.01) affected by Zn levels and cultivars, while the interaction effects of Zn level × cultivars were only significant (P≤0.01) for root, shoot and grain Zn concentrations. Mean comparisons of the interaction effects revealed that under soil Zn deficiency, the concentration of root Zn in Zn-efficient cultivars (Nik-nejhad: 59 mg kg-1, Bayat: 44.75 mg kg-1) is significantly (P≤0.01) more than those of Zn-inefficient cultivars (Hirmand: 30.58 mg kg-1, Karaj-1: 32.98 mg kg-1). The grain Zn concentration of Bayat (28.82 mg kg-1) cultivar was also significantly (P≤0.01) more than those of Zn-inefficient cultivars (Hirmand: 24.95 mg kg-1 and karaj-1: 22.85 mg kg-1). The estimation of trait decline percentage under soil Zn deficiency revealed more decrease for shoot dry weight, root and grain Zn concentrations and chlorophyll content in Zn-inefficient cultivars, compared to Zn-efficient ones. In conclusion, the results of the current study demonstrated that Zn-efficient bread wheat cultivars are able to produce more dry matter and accumulate more Zn in grains under soil Zn deficiency conditions.