**4. Conclusions**

Because awns presumably have photosynthetic activity, awned and awnletted wheat cultivars were compared for their 1000-grain weight, mineral composition and Fe speciation and Fe local chemical environment. While there was no di fference in 1000-grain weight, a larger Ca and Mn, but smaller Fe concentrations, were found in whole grain of awned than in awnletted cultivars. Genetic and/ or metabolic reasons behind the observed di fferences in mineral composition will need to be studied in future experiments. The evaluation of Fe speciation and Fe ligands revealed that di fferences in total Fe concentration were not accompanied by di fferences in Fe speciation (on average 64% of Fe existed as ferric and 36% as ferrous species) or Fe ligands (on average 53% were phytate and 47% were non-phytate ligands) in the two awned and two awnletted cultivars studied using micro-XANES. Contrastingly, there was a distinct tissue-specificity with pericarp containing the largest proportion (86%) of ferric species and nucellar projection (49%) the smallest. Iron was predominantly bound to phytate in aleurone, scutellum and embryo (72%, 70%, and 56%, respectively), while in nucellar projection and pericarp Fe was bound only to non-phytate ligands. Assuming Fe bioavailability depends on Fe ligands, we conclude that Fe bioavailability from wheat grain is tissue specific.
