Bread wheat genetic variation for grain's protein, iron and zinc concentrations as uptake by their genetic ability

Genetic diversity among 80 irrigated bread wheat genotypes was studied for their grain's protein, iron and zinc concentrations as well as agronomic traits. The trend of these traits over the 70 years of cultivar releasing was demonstrated. The experiment was conducted as a RCBD with three replicates under normal and terminal drought stress conditions in Kermanshah, Iran during 2011-2012 cropping season. The results of combined ANOVA revealed high significant genotypic differences for all traits, except grain iron and zinc yield. Terminal drought stress reduced all studied traits except grain iron concentration which it increased by 14.10%. The maximum effect of drought stress was on grain zinc yield, grain yield and thousand grain weight as much as 26.65, 23.48 and 18% reduction, respectively. In both conditions, there were negative correlations among grain yield and grain iron, zinc and protein concentrations. Moreover, it was found that grain yield was increased with a small improvement during 70 years while protein, iron and zinc concentrations were decreased over the years. A wide range of genetic diversity in micronutrients uptake, particularly iron and zinc within studied wheat genotypes was identified which suggesting that selection for improved micronutrients efficiency is possible. What was concluded from this study is breeders' attention to enhancing grain production caused to neglect the quality of wheat production specially protein, iron and zinc concentrations during the last 70 years. (C) 2015 Elsevier B.V. All rights reserved.