Distribution of Zinc in Bread Wheat Genotypes with High and Low Zn-content

Zinc (Zn) is an essential micronutrient that is crucial to the health of all organisms. Zn absorption through roots system during the grain-filling period and Zn remobilization from pre-anthesis stores of shoot into grains are two main sources of zinc accumulation in grains. Field and solution experiments were conducted to study the Zn efficiency in two groups of Iranian bread wheat (Triticum aestivum L.) genotypes with high and low Zn content in seeds at two vegetative stages. Among 110 evaluated genotypes, six and seven were selected with high and low seed Zn content, respectively. Assessment of zinc uptake, accumulation and utilization in shoot, root, and shoot dry weight traits showed significant differences between two genotypic groups only at 60 days after planting (DAP). The genotypes with high seed Zn content showed higher uptake, accumulation and utilization of zinc in shoot than those with low seed Zn content. Our results showed Zn efficient genotypes are detected not only by Zn uptake but also by accumulation and utilization of Zn in the shoot. Among the mechanisms involved in Zn efficiency, Zn uptake and/or utilization are likely more influential. The root-to-shoot translocation ratio was at the same rate between these two groups. Our results showed that Zn uptake and accumulation in shoot among genotypes can be considered as a useful parameter for revealing impairments of efficiency in wheat genotypes.