Durum wheat quality traits affected by mycorrhizal inoculation, water availability and atmospheric CO2 concentration

Predicted reduced precipitation, enhanced evaporative demand and increasing CO2 in the atmosphere will strongly influence wheat production. The association of wheat with arbuscular mycorrhizal fungi (AMF) improves growth under stressful conditions. Our objective was to test the influence of mycorrhizal inoculation on yield, and accumulation of macro- and micro-nutrients and gliadins in grains of durum wheat (Triticum durum Desf.) plants grown under different CO2 concentrations and water regimes. The main factors of the experimental design were mycorrhizal inoculation (inoculated or non-inoculated plants); atmospheric CO2 concentration (ambient, ACO2, or elevated, ECO2); and water regime (optimal or restricted water regime). At ACO2, the simultaneous application of AMF and water deficit decreased the number of seeds per spike without affecting the biomass of grains, and grains accumulated higher contents of copper, iron, manganese, zinc and gliadins. The opposite effect was observed with ECO2 where, regardless of mycorrhizal and water treatment factors, a general depletion of contents of micro- and macro-nutrients and gliadins was detected. Whereas mycorrhizal inoculation together with drought applied to plants cultivated at ACO2 improved wheat grain quality parameters, under ECO2, mycorrhization did not ameliorate grain quality parameters detected in plants that produced the largest grain dry matter values.