The influence of inoculation and drought on the diversity of fungal communities in the roots of tomato plants

Arbuscular mycorrhizal fungi (AMF) are microorganisms with very important functions in agricultural systems. Since arbuscular mycorrhiza is one of the most common types of mycorrhizae, the diversity of AMF is very varied. Their diversity can be influenced by various biotic and abiotic factors. Of these, drought is one of the most common abiotic stresses in agriculture. In this study, we evaluated the influence of drought and inoculation with three species of AMF (Rhizoglomus irregulare, Funneliformis mosseae and F. caledonium) on the fungal genetic diversity in the roots of tomato plants (Solanum lycopersicum L.) using partial 18S rRNA gene in molecular fingerprinting method. Two conserved primer pairs NS1–NS4 and NS31–AM1 in Nested PCR were used. The second primer pair is specific for AM fungi from Glomeromycota, but also amplifies DNA from Ascomycota and Basidiomycota to a very small extent. Drought caused a decrease in fungal alpha diversity in tomato roots of non-inoculated plants. On the other hand, an increase of this diversity due to drought in inoculated plants was observed. Based on principal component analysis, a statistically significant shift in the composition of fungal communities in non-inoculated and inoculated plants due to drought was not detected. At the same time, the most variable fungal communities were in control well-watered and non-inoculated plants, but this variation was not significant.