Shelf-life and storage conditions of AMF inocula: a neglected factor in inoculum application

The application of arbuscular mycorrhizal fungi (AMF) inocula in crop production is known for its benefits on plant yield and rhizosphere interactions. However, some aspects of AMF inoculant production lack standardization and characterization, such as storage conditions, which may directly affect inoculum efficiency and infectivity. Thus, this opinion paper aimed to summarize the research on AMF inoculant storage, highlight the most decisive factors in mycorrhizal inoculant production, understudied, such as cryopreservation and alginate beads, to preserve AMF propagules, and what the next steps are in the research on AMF inoculant storage. Taken together, this paper is a call for a deeper investigation into AMF inoculum production to assist the development of efficient commercial inoculants.