Arbuscular mycorrhizal colonization by five isolates of Glomeromycotan fungi after storage along a year at two contrasting temperatures with Vigna luteola as test plant.

Due to the important functions of arbuscular mycorrhizas (AM), they are considered crucial for both agriculture and reforestation. Although mycorrhizal inoculant production has grown significantly, information about the effect of time and storage conditions on its performance is very scarce. The aim of this study is to assess the infectivity of five different AMF inocula, stored along a year at two contrasting temperatures (2 and 20 °C). Plant growth, percentage of mycorrhizal colonization (AM%), arbuscules (Arb%) and vesicles (Ves%) were assessed monthly, using Vigna luteola as test plant. Acaulospora lacunosa, Funneliformis mosseae, and Gigaspora gigantea presented a better performance when they were stored at 20 °C than at 2°C, while Rhizoglomus manihotis and Dentiscutata heterogama were not affected by the temperature of storage. Inoculants had a positive effect on plant growth throughout the year, reaching a maximum value after 4 months of storage. AM% and Arb% decreased throughout the year of storage, whereas Ves% remained high in R. manihotis (both temperatures) and A. lacunosa (20°C). These findings are discussed in light of the biology of the evaluated AMF species. The inoculants produced must be stored at room temperature for greater preservation of their infective capacity.