Propagules and mycorhizal formation in road slopes, in southern Minas Gerais state, Brazil

Abstract

Slope areas are impacted due to the cutting at depth of the soil, making it difficult to revegetate. However, even with physical and chemical limitations in soil quality, growth and/or survival of plant species have been observed. Slope soils, besides the low fertility, are still usually eroded. For these cases, microorganisms, such as arbuscular mycorrhizal fungi, can contribute to increase availability of nutrients for plants and soil aggregation, thereby aiding the process of revegetation of these areas. In this sense, the objective of this study was to characterize physically and chemically six cutting slope revegetated naturally on a stretch of road MGC-383, in southern Minas Gerais state, in two depths (0-20 and 20-50 cm), relating them to the presence of propagules from arbuscular mycorrhizal fungi (AMF) by the density and diversity of spores, total extraradical mycelium length, percentage and intensity of root colonization, using descriptive and multivariate statistics. The results showed high density of propagules of AMF, with low diversity of species, presenting dominance of species Acaulospora mellea, Acaulospora scrobiculata and Paraglomus brasilianum. The plants were highly mycotrophic, with mycorrhizal colonization up to 74%. The occurrence of AMF propagules and mycorrhiza formation showed that mycorrhiza can be a mechanism adopted for plants during the natural revegetation process of road slopes.