Effect of spontaneous arbuscular mycorrhizal colonization in bread wheat varieties on the incidence of foliar diseases and grain yield

This study aimed to determine the ability of different wheat genotypes to form a symbiosis with arbuscular mycorrhizal fungi (AMF) present in the field and the effect of such a symbiosis on disease severity and grain yield. A bioassay was performed during an agricultural cycle under field conditions in a randomized block factorial design. The factors used were application of fungicide (two levels: with and without fungicide) and wheat genotypes (six levels). Arbuscular mycorrhizal colonization, green leaf area index, and severity of foliar diseases were evaluated in the tillering and early dough stages. At maturity, the number of spikes per square metre the number of grains per spike, and the thousand-kernel weight were determined to estimate grain yield. In addition, the spores of Glomeromycota present in the soil were identified by morphological techniques. Spores belonging to 12 fungal species were recovered. Genotypic variability was found for arbuscular mycorrhization, with the cultivars Klein Liebre and Opata exhibiting the highest colonization values. The results obtained show a beneficial effect of mycorrhizal symbiosis on foliar disease resistance and grain yield in the controls, but the results varied in the case of fungicide treatment. A greater understanding of the ecological role of these microorganisms in agricultural systems can lead to more sustainable agronomic practices.