Zinc application alleviates drought stress in bread and durum wheat genotypes under dryland conditions

Drought stress and zinc (Zn) deficiency are abiotic stress factors limiting crop production in Iran, especially in rainfed areas. In this study, the effects of Zn application and drought stress was investigated on grain yield of 10 wheat cultivars (6 bread wheat and 4 durum wheat) grown in a Zn-deficient calcareous soil over 2 years under rainfed condition in Dryland Agricultural Research Institute (DARI) where drought causes substantial yield reduction. Plants were treated with (+Zn: 10 kg Zn/h, as ZnSO4.7H2O) and without Zn (-Zn) under rainfed condition in a randomized complete Block Design (RCBD) with 3 replications. Zinc fertilization could enhance biomass, harvest index and grain weight of genotypes that resulted in 7% grain yield increase on average in both years. Increases in grain yield varied among genotypes from 1% to 16%, and durum genotypes showed higher rising. Accordingly, there was variability in Zn efficiency of genotypes (ratio of grain yield under Zn deficiency compared to that under Zn fertilization). Durumwheat genotypes generally showed low levels of Zn efficiency and grain yield under Zn deficiency. Overall, there was a poor relation between Zn-efficiency values and grain yield increase. The results presented here demonstrate the existence of variation in Zn efficiency among bread and durum wheat genotypes, and suggest the possibility of breeding for higher grain yield and improving Zn efficiency in Zn-deficient calcareous soils under rainfed conditions. Moreover, Zn application would increase bread and especially durum wheat productivities in drylands.

کلیدواژه ها:

Genotypic variation ، Zinc application ، Drought tolerance ، Bread and durum wheat