Conclusion

This study presents the first inventory of AMF associated with olive trees in southern Brazil, documenting six species from five genera and four families, representing distinct functional groups previously reported in olive cultivation systems. Four species: _G. ambisporu_m, _G. decipien_s, G. rosea, and D. globifera, were present in all sampling units and can be characterized as stable and generalist components of the AMF community associated with olive cultivation in the region, regardless of the cultivar. This work establishes an initial ecological baseline for future studies to complement the understanding of AMF-olive interactions and to subsequently support the production of regionally adapted mycorrhiza-based bioinputs.

Taken together, the results suggest that AMF communities associated with olive trees are composed of stable and cultivar-shared taxa, whereas differences in the abundance of some species indicate that host genotype may contribute to shaping community composition. The predominance of members of the Glomeraceae family and their coexistence with representatives of the Gigasporaceae suggest the presence of functionally contrasting groups within the system, highlighting the potential of genera such as Glomus and Gigaspora for future studies on symbiotic efficiency and the development of regionally adapted inoculants.

However, given the associative nature of the evidence and the methodological limitations of the present study, these patterns require confirmation through studies with greater replication, temporal sampling, and molecular characterization. Further studies are also needed to experimentally evaluate the functional role of these taxa in olive tree growth and nutrition, as well as to investigate the temporal dynamics and broader taxonomic diversity of AMF communities associated with olive cultivation in southern Brazil.