Strong increase of durum wheat iron and zinc content by field-inoculation with arbuscular mycorrhizal fungi at different soil nitrogen availabilities

Since actual production of wheat often leads to human Fe and Zn deficiency, a better understanding of the potential of arbuscular mycorrhizal fungal (AMF) inoculation for micro-nutrient uptake of durum wheat is needed. Effects of AMF field inoculation and N availability were evaluated on an old and a modern durum wheat variety Following AMF inoculation, the modern variety showed a higher increase of the early root colonization respect to the old one, whereas at maturity root colonization was decreased by N fertilization. In the old variety grain N concentration was increased by inoculation when plants were not fertilized and at the 40-0-40 N, whereas in the modern variety inoculation did not change N concentration. By contrast, in AMF inoculated plots the modern variety showed a higher increase of Fe and Zn in grain compared to the old variety. Accordingly, at harvest, the modern variety showed an higher increase of a molecular operational taxonomic unit affiliated to Rhizophagus compared to the old variety. The inoculated isolate is a good durum wheat colonizer and the modern variety showed higher responsiveness to inoculation in terms of N, Fe and Zn grain concentration respect to the old one.