title: Nitrogen-fixing bacteria and arbuscular mycorrhizal fungi in Piptadenia gonoacantha (Mart.) Macbr.
abstract: The family Leguminosae comprises approximately 20,000 species that mostly form symbioses with arbuscular mycorrhizal fungi (AMF) and nitrogen-fixing bacteria (NFB). This study is aimed at investigating and confirming the dependence on nodulation and biological nitrogen fixation in the specie Piptadenia gonoacantha (Mart.) Macbr., which belongs to the Piptadenia group. Two consecutive experiments were performed in a greenhouse. The experiments were fully randomized with six replicates and a factorial scheme. For the treatments, the two AMF species and three NFB strains were combined to nodulate P. gonoacantha in addition to the control treatments. The results indicate this species' capacity for nodulation without the AMF; however, the AMF+NFB combinations yielded a considerable gain in P. gonoacantha shoot weight compared with the treatments that only included inoculating with bacteria or AMF. The results also confirm that the treatment effects among the AMF+NFB combinations produced different shoot dry weight/root dry weight ratios. We conclude that AMF is not necessary for nodulation and that this dependence improves species development because plant growth increases upon co-inoculation.
authors.affiliation: Universidade Federal Rural do Rio de Janeiro (UFRRJ), Seropédica, RJ, Brazil. Electronic address: joelquintino@yahoo.com.br.
authors.forename: Joel Quintino de Oliveira
authors.initials: JQ
authors.lastname: Júnior
authors.affiliation: Embrapa Agrobiologia, Seropédica, RJ, Brazil.
authors.forename: Ederson da Conceição
authors.initials: ED
authors.lastname: Jesus
authors.affiliation: Universidade Federal Rural do Rio de Janeiro (UFRRJ), Departamento de Solos, Laboratório de Biologia do Solo, Seropédica, RJ, Brazil.
authors.forename: Francy Junio
authors.initials: FJ
authors.lastname: Lisboa
authors.affiliation: Universidade Federal Rural do Rio de Janeiro (UFRRJ), Departamento de Solos, Laboratório de Biologia do Solo, Seropédica, RJ, Brazil.
authors.forename: Ricardo Luis Louro
authors.initials: RL
authors.lastname: Berbara
authors.affiliation: Embrapa Agrobiologia, Seropédica, RJ, Brazil.
authors.forename: Sergio Miana de
authors.initials: SM
authors.lastname: Faria
mesh_terms: D007887:Fabaceae / Q000382:microbiology*; D038821:Mycorrhizae; D009586:Nitrogen Fixation; D000072738:Nitrogen-Fixing Bacteria; D055170:Plant Root Nodulation; D053204:Root Nodules, Plant / Q000382:microbiology; D013559:Symbiosis
keywords: Biological nitrogen fixation; Nodulation; Synergy; “Pau-jacaré”