Lotus associated soil microorganism in agricultural practices. Communities stability and technology use

BAILLERES, M; CAMPESTRE; LLAMES ME; NIEVA, S; ANTONELLI; ESCARAY F; O. A. RUIZ; GARRIZ A; MJ CORRIALE; ANA BERNARDINA MENENDEZ

Londrina

Conferencia; XXVII Reunión Latinoamericana de Rizobiologia; 2016

Sociedad Iberoamericana de Rhizobiología

Lotus ASSOCIATED SOIL MICROORGANISM IN PASTUREIMPLANTATION COMMUNITIES STABILITY ANDTECHNOLOGICAL USEAmira S. Nieva1, Matias Bailleres2, Andres Garriz1, Cristian Antonelli1,Maria Paula Campestre1, Maria Jose Corriale3, Francisco Escaray1,Maria Eugenia Llames1, Ana B. Menedez3, Oscar A. Ruiz11IIB INTECH, Chascomus, Argentina, ruiz@intech.gov.ar; 2CEICh; 3FCEN-UBAThe forage legume Lotus tenuis is an appealing alternative to meet the needs forcattle production in the Flooding Pampa region, Argentina. The use of chemicalcompounds for agriculture practices, in addition to the removal of native vegetation,eventually may change the diversity of other ecosystem components such as bacterialcommunities. To examine the effect of L. tenuis promotion with herbicides on the soilbacterial community and taxonomic composition, we studied three different rangelandsites of the Flooding Pampa region. At each site, two paddocks were compared: onemanaged to promote the forage legume L. tenuis and the other lacking of managementhistory and hence, covered by natural grasses. To asses bacterial diversity we used454-FLX pyrosequencing technology of the V4 region of the 16S rRNA gene and ITSregion, on genomic DNA extracted from soil samples. Our results suggest that 5-6years of land use with L. tenuis promotion does not affect the bacterial communitystructure in this ecosystem, evidenced in the non-differences between the treatmentsfor diversity indices there are a lot of soil microorganism living inside plant tissues.Endophytes microorganism provide a wide range of benefits to their hosts, as nutrientavailability, protection from herbivores and pathogens, inorganic carbon and nitrogenfixation and others. Its potential use as biofertilizers can become a sustainable lowcosttechnology. However it has been shown that endophytes-plant interactions arehighly variable in the ecosystem, occurring along the continuum from antagonistic tomutualistic interactions. Fungal endophytes isolated from lotus roots were evaluatedaccording their phosphate solubilizing capability and tolerance to soil extremeconditions. Our results, shown that several strains grow well, in a wide pH range andsalinity conditions. Two Lotus species were infected by one of the isolated strains. Theinteraction effect was contrasting between them, evidenced by a growth promotion inone versus a decrease in biomass production in the other one. These results suggestthat the use of fungal endophytes as biofertlizers should be studied in depth before itsuse in a specific host.Keywords: Pastures in constrained soils; FBN and P solubilization; PGPB and fungi.