Indigenous Arbuscular Mycorrhizal Fungi Consortium Enhances Growth and Protects Boufeggous Gharas Date Palm Against <i>Fusarium oxysporum</i> f. sp. <i>albedinis</i> Infection in Figuig Oasis (Morocco)

An indigenous consortium of arbuscular mycorrhizal fungi (AMF) from the Figuig oasis in southern Morocco, comprising <i>Rhizophagus</i> sp., <i>Funneliformis</i> sp., <i>Acaulospora</i> sp., <i>Sclerocystis</i> sp., and <i>Scutellospora</i> sp., was evaluated for its effects on the growth and sensitivity of <i>Phoenix dactylifera</i> L. variety (cv. Boufeggous Gharas) to <i>Fusarium oxysporum</i> f. sp. <i>Albedinis</i> (Foa), the causal agent of Bayoud disease. Despite its high fruit quality and local appreciation, the Boufeggous Gharas variety is highly susceptible to Foa and is currently at risk of extinction, underscoring the urgent need for its sustainable management. The results demonstrated that Boufeggous Gharas seedlings inoculated with a consortium of indigenous AMF showed significantly improved shoot and root length, leaf number, and biomass as compared to non-mycorrhized seedlings. In contrast, Foa-infected seedlings showed significantly reduced growth, with a 46.6% decrease in shoot height and a 50.4% reduction in root length compared to non-infected seedlings. Interestingly, AMF inoculation mitigated this sensitivity to Foa, significantly restoring growth parameters. Seedlings treated with AMF + Foa showed a 51% increase in shoot height and a 61% improvement in root length, along with over 100% gains in shoot and root biomass compared to seedlings infected solely with Foa. This study provides the first evidence of integrating AMF into sustainable date palm cultivation practices to mitigate the impacts of biotic stresses, thereby promoting the preservation and valorization of vulnerable date palm varieties. The protective effects of AMF are attributed to improved nutrient uptake, enhanced root architecture, and systemic resistance induced by AMF colonization.