In the ‘AC2S-Agriculture and Food under the Sun of Sardinia’ project, the contribution of the Plant-Soil Interactions research group of the Sant'Anna School of Institute of Crop Science
In the AC2S-Agriculture and Food under the Sun of Sardinia project, the Plant-Soil Interactions research group of the Institute of Crop Science of the Sant'Anna School carried out a study to investigate the effect of field inoculation with a consortium of arbuscular mycorrhizal fungi (AMF) and bacteria on the productivity of local and modern durum wheat genotypes and semolina quality.
The objective was to test the hypothesis that a consortium of mycorrhizal fungi could improve durum wheat performance by increasing the abundance of endophytic fungi and bacteria, i.e. in the roots. The consortium applied consisted of five species of mycorrhizal fungi, Trichoderma harzianum, and four species of bacteria, including Pseudomonas fluorescens. The trials took place in Sardinia, on three farms located in Cabras, Pabillonis and Villanovafranca. Three modern durum wheat genotypes (Estedur, Shardana and Nuraghe) and two ancient ones (Murru and Russello) were tested. Inoculation was applied by seed treatment. Inoculation almost doubled the yield in the clay and moderately alkaline soils of Cabras, while in Pabillonis (clay loam soils, neutral pH) the increases were 60%. At Villanovafranca, only the modern Estedur genotype showed a significant improvement. The lower bacterial biomass in the treated roots indicates a higher competition of the inoculated fungi against root pathogens. At Cabras, Shardana and Russello also showed an increase in nitrogen content, while at Pabillonis this effect was observed in Shardana and Nuraghe.
With regard to phosphorus, better absorption was observed in the Shardana and Nuraghe genotypes at Cabras and in Estedur and Nuraghe at Villanovafranca, with a 10% increase in all genotypes at Pabillonis. Finally, the iron and zinc content in the grain was significantly increased by treatment with fungi and bacteria in Shardana and Rusello in Shardana, and in Estedour in Villafranca. In Papillonis, in a relatively less fertile and more tired soil, all varieties responded positively to inoculation in terms of increase in iron, while Shardana and Nuraghe in terms of increase in zinc.
The study shows that the response of wheat to microbial inoculation is closely dependent on environmental factors and the identity of the plant and microorganism. In summary, selecting compatible combinations of variety, microbial consortium and environmental conditions is crucial to optimise results. Future studies will investigate whether these benefits persist in processed products, such as pasta or pane carasau.
