Endomycorrhizal fungi inoculation improves development of Stevia (Stevia rebaudiana Bertoni) plantlets during ex vitro acclimatization

Arbuscular mycorrhizal fungi (AMF) establish symbiotic associations with plants and improve the productivity of agricultural crops. This study aimed to evaluate the effect of different doses of the fungus Glomus intraradices on the development of stevia (Stevia rebaudiana Bertoni) plantlets during the acclimatization stage. Stevia plantlets obtained in vitro were inoculated with different doses (0, 50, 150, 300 and 450 spores per plantlet) of G. intraradices. After 60 days of acclimatization, the colonization and survival percentages, plant development, and dry matter, chlorophyll, carotenoid, and macro- and micronutrient contents were evaluated. An effect of mycorrhizae on the different variables evaluated was observed. The dose of 150 spores per plantlet, with 34% colonization, achieved an efficient symbiotic interaction, whereas, at a dose of 0 and 450 spores per plantlet, with 0 and 44% colonization, respectively, there was a lower survival rate and poor development. Early application of adequate doses of mycorrhizae on stevia plantlets favors survival and physiological development. The fungus-plant symbiosis could represent a pre-transplant conditioning advantage for stevia crop establishment.