Historical land use determines arbuscular mycorrhizal communities regardless of decades since intensive agricultural conversion

CABELLO, MN; DANIELL, T; FAGGIOLI, VS; COVACEVICH, F; LANGARICA-FUENTES A

Praga

Conferencia; IX International Conference on Mycorrhiza; 2017

ICOM

The objective of this study was to investigate the effect of historical land use (HLU) on AMF communities indigenous of current soybean fields. Representative soil and root samples were taken from three areas according to the period since agricultural conversion: Forest (50 years). A total of 125 sites were sampled following a gridline method in central Argentinean Pampas. AMF spores were isolated and morphologically identified both from fresh field soils and after multiplication in trap cultures. DNA extraction, 18S RNA amplification and Terminal Restriction Fragments (T-RFLP) approaches were assessed to study AMF patterns in soybean roots. A total of 36 species were found belonging to 7 families: Ambisporaceae, Acaulosporaceae, Claroideoglomeraceae, Diversisporaceae, Entrophosporaceae, Gigasporaceae and Glomeraceae. The most frequently occurring species in the study were Acaulospora scrobiculata, Claroideoglomus etunicatum, Funneliformis mosseae y Glomus fuegianum. Forest sites exhibited significantly higher richness followed by Livestock and Agricultural sites. The same pattern was found with the number of AMF T-RFLPs in roots. Pairwise comparison of communities based on spore abundances showed that each HLU was different to another. T-RFLPs revealed that soybean grown in Forest sites had a community structure different from Livestock and Agricultural sites, but the formers did not differed between them. In conclusion, HLU strongly determined AMF community composition and richness in spite of being currently submitted to soybean cultivation practices. Future works should to examine how colonizing AMF communities change in order to avoid the loss of specific groups of AMF which could affect agriculture sustainability.