12 3 Iron and zinc grain density in common wheat grown 4 in Central Asia 5

18 1 (mean 28 mg kg). Spring wheat cultivars pos19 sessed higher Fe-grain concentrations than winter 20 wheats. By contrast, winter wheats showed higher 21 Zn-grain concentrations than spring genotypes. 22 Within spring wheat, a strongly significant positive 23 correlation was found between Fe and Zn. Grain 24 protein content was also significantly (P < 0.001) 25 correlated with grain Zn and Fe content. There 26 were strong significantly negative correlations 27 between Fe and plant height, and Fe and glutenin 28 content. Similar correlation coefficients were 29 found for Zn. In winter wheat, significant positive 30 correlations were found between Fe and Zn, and 31 between Zn and sulfur (S). Manganese (Mn) and 32 phosphorus (P) were negatively correlated with 33 both Fe and Zn. The additive main effects and 34 multiplicative interactions (AMMI) analysis of 35 genotype · environment interactions for grain Fe 36 and Zn concentrations showed that genotype 37 effects largely controlled Fe concentration, 38 whereas Zn concentration was almost totally 39 dependent on location effects. Spring wheat 40 genotypes Lutescens 574, and Eritrospermum 78; 41 and winter wheat genotypes Navruz, NA160/ 42 HEINEVII/BUC/3/F59.71//GHK, Tacika, DU43 CULA//VEE/MYNA, and JUP/4/CLLF/3/ 44 II14.53/ODIN//CI13431/WA00477, are promising 45 materials for increasing Fe and Zn concentrations 46 in the grain, as well as enhancing the concentra47 tion of promoters of Zn bioavailability, such as S48 containing amino acids.