Occurrence and diversity of arbuscular mycorrhizal fungi in trap cultures from soils under different land use systems in the Amazon, Brazil

Abstract

The aim of this work was to evaluate the occurrence of arbuscular mycorrhizal fungi (AMF) species diversity in soil samples from the Amazon region under distinct land use systems (Forest, Old Secondary Forest, Young Secondary Forest, Agroforestry systems, Crops and Pasture) using two distinct trap cultures. Traps established using Sorghum sudanense and Vigna unguiculata (at Universidade Regional de Blumenau -FURB) and Brachiaria decumbens and Neonotonia wightii (at Universidade Federal de Lavras -UFLA) were grown for 150 days in greenhouse conditions, when spore density and species identification were evaluated. A great variation on species richness was detected in several samples, regardless of the land use systems from where samples were obtained. A total number of 24 AMF species were recovered using both methods of trap cultures, with FURB´s traps yielding higher number of species. Acaulospora delicata, A. foveata, Entrophospora colombiana and two undescribed Glomus species were the most abundant and frequent species recovered from the traps. Number of species decreased in each genus according to this order: Acaulospora, Glomus, Entrophospora, Gigaspora, Archaeospora, Scutellospora and Paraglomus. Spore numbers were higher in Young Secondary Forest and Pastures. Our study demonstrated that AMF have a widespread occurrence in all land use systems in Amazon and they sporulate more abundantly in trap cultures from land uses under interference than in the pristine Forest ecosystem.

Links between plant and fungal communities across a deforestation chronosequence in the Amazon rainforest

“…In tropical ecosystems, the responses of soil fungal biodiversity to land-use change are only beginning to be explored, and responsiveness has been shown in some cases (for example, Fracetto et al, 2013) but not in others (for example, Leal et al, 2009). Fungal communities can be structured by nutrient availability (Rousk et al, 2010) and plant community composition (Carney and Matson, 2006;Peay et al, 2013), suggesting that shifts in soil fungal communities in response to land-use change (Castro et al, 2008;Fracetto et al, 2013) could result from alterations in soil properties and/or plant communities.…”

Changes in Land Use System and Environmental Factors Affect Arbuscular Mycorrhizal Fungal Density and Diversity, and Enzyme Activities in Rhizospheric Soils of Acacia senegal (L.) Willd.

“…Klironomos and Hart [42] described large between-and within-site variations in the composition of AMF communities. Physical and chemical properties of soil and climatic factors such as soil moisture might explain differences observed between Dahra and Goudiry sites [43,44]. The effect of land uses (plantation versus natural population) on the diversity of AMF was noticed in the site of Dahra, but not in that of Goudiry.…”

Genetic and Functional Diversities of Microbial Communities in Amazonian Soils Under Different Land Uses and Cultivation

“…Since AMF produce spores significantly bigger than the other fungi species, it is possible to separate them from soil samples by sieve and centrifugation in a sucrose gradient. Up to now, the studies in Brazilian Amazon were made using this approach (Leal et al, 2009;Mescolotti et al 2010;Stürmer and Siqueira, 2010). In Southwestern Amazon an AMF study compared three land uses: native vegetation, soybean fields and pastures, in two regions: Sinop (Forest) and Campo Verde (Cerrado), both in Mato Grosso State, Brazil (Mescolotti et al, 2010).…”