Temporal dynamics of the mycorrhizal inoculum potential of fungal communities in reference ecosystems for strawberry cultivation in southern Brazil

One of the alternatives for making the strawberry production system more sustainable is arbuscular mycorrhizal fungi (AMF). However, there are few commercial inoculants based on AMF. This shortage can be attributed to the information scarcity on the temporal dynamics of mycorrhizal inoculum potential (MIP). Here, we investigated whether there is temporal variability in the MIP of AMF communities in cultivated and native forest soils in reference ecosystems for strawberry cultivation. The treatments were nine inoculants (eight soils containing AMF communities and Rhizophagus clarus as a control) not subjected (year 2016) or subjected (year 2020) to storage. The experimental design was entirely randomized, with three replicates. The inoculants used were grouped into three strata in terms of mycorrhizal colonization. R. clarus showed the greatest infective capacity on sorghum roots, followed by inoculants from native forest soils, and finally, inoculants from soils cultivated with strawberries. The highest MIP was observed in non-stored inoculants in the experiment set up in 2016. In conclusion, there is temporal variability in the MIP of AMF communities in cultivated and native forest soils in reference ecosystems for strawberry cultivation. Natural soils and those not stored have a greater capacity to colonize the roots of the plant host.