Detecção de Azospirillum amazonense em raízes e rizosfera de orchidaceae e de outras famílias vegetais

Lange, A. De; Moreira, F. M. S.

doi:10.1590/s0100-06832002000200027

Cited by 9 publications

(6 citation statements)

References 2 publications

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“…This could be due to the higher bacterial densities in Fam media pasture soil cultures. This medium was also more efficient in culturing diazotrophic bacteria from the roots and the rhizospheres of Orchidaceae and other plants compared to LGI medium (Lange and Moreira, 2002), most likely because of the presence of micronutrients that Colony characterization of isolates and type and reference strains revealed high phenotypic diversity, with 25 phenotypically groups being identified (Figure 2). The only similar characteristic among all isolates was days of growth for the appearance of isolated colonies (1 to 2 days).…”

Section: Resultsmentioning

confidence: 99%

Density and diversity of diazotrophic bacteria isolated from Amazonian soils using N-free semi-solid media

Silva¹,

Nóbrega²,

Lima

et al. 2011

Sci. agric. (Piracicaba, Braz.)

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Non-symbiotic diazotrophic bacteria are amongst the most important functional groups of soildwelling microorganisms. These bacteria contribute to plant growth predominantly through biological N 2 fixation. Here, we evaluated the density and diversity of non-symbiotic diazotrophic bacteria in soils taken from diverse land use systems (LUS) in Amazonia using nitrogen-free media. A total of 30 soil samples were collected from the following LUS: pristine forest, young secondary forest, old secondary forest, agroforestry, agriculture and pasture. Bacterial density was evaluated by the most probable number (MPN) method utilizing N-free semi-solid media with varied compositions (JNFb, NFb, LGI and Fam). Individual isolates were characterized by colony and cellular morphology as well as total protein profiles and nitrogenase activity. Isolate genotypes were determined by partial 16S rDNA sequences. No typical diazotrophic growth in the JNFb medium was observed. Bacterial densities in the NFb medium were higher in the agriculture and agroforestry soil samples. In LGI and Fam media, bacterial densities were highest in the pasture soil samples. Overall, 22 isolates with high phenotypic diversity were obtained. Eleven isolates exhibited nitrogenase activity. Sequences of 16S rDNA genes of 14 out of 19 isolates had similarities below 100 % with known nitrogen-fixing species. Isolates were identified as belonging to the Burkholderia, Enterobacter, Serratia, Klebsiella, and Bacillus genera. A higher number of isolates from pasture soil samples were isolated, with the majority of these belonging to the Burkholderia and Bacillus genera. Among the isolates, unknown sequences were obtained, possibly indicating new species. Taken together, these data demonstrate that Fam, NFb, and LGI semi-solid media allowed the growth of diazotrophic bacteria belonging to different phylogenetic lines.

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Section: Resultsmentioning

confidence: 99%

Density and diversity of diazotrophic bacteria isolated from Amazonian soils using N-free semi-solid media

Silva¹,

Nóbrega²,

Lima

et al. 2011

Sci. agric. (Piracicaba, Braz.)

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“…A micotrofia desenvolveu-se fortemente entre as orquidáceas, no entanto diversos grupos basais de epífitas também podem apresentar esta associação (Benzing 1990). Especula-se, também, o importante papel de determinadas bactérias associadas ao sistema radicular de orquídeas (Rasmussen 2002), havendo, inclusive, relato da ocorrência de fixadores de N 2 no substrato de crescimento e na ecto e endo-rizosfera de várias espécies coletadas no Brasil (Lange & Moreira 2002).…”

Section: Evolução E Estratégias Adaptativasunclassified

Epífitas vasculares: histórico, participação taxonómica e aspectos relevantes, com ênfase na Mata Atlântica

Kersten

2010

Hoehnea

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O Dossel é um ecossistema complexo e ecologicamente diverso, possuindo espécies, nichos e processos próprios. Dentre as diversas formas de vida que o compõem, destaca-se a epífita. Este trabalho procurou reunir informações sobre esta sinúsia estabelecendo padrões florísticos para as epífitas no bioma Mata Atlântica. A maioria das epífitas é monocotiledônea (63,5%), seguida das Monilophyta (16,4%), Eudicotiledôneas (14,1%), Magnoliídeas (4,5%) e Lycophyta (1,6%). As famílias mais ricas são Orchidaceae com 45,8 % das espécies, Bromeliaceae com 12,9%, Polypodiaceae, com 5,5%, Araceae, com 5,0% e Piperaceae, com 4,7%. O bioma inteiro suporta, possivelmente, até cerca de 3.300 espécies, 69% das quais observadas em zonas ecotonais, 60,6% na Floresta Ombrófila Densa, 42,4% nas Formações Edáficas de Primeira Ocupação, 25,5% nas Florestas Estacionais e 22,5% na Floresta Ombrófila Mista. São ainda apresentadas sessões sobre histórico dos estudos sobre epífitas, composição taxonômica, importância ecológica, distribuição geográfica, classificação, evolução e estratégias adaptativas e distribuição espacial, contendo revisão bibliográfica atualizada sobre estes assuntos.

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“…Although rhizobacteria are known to have a great and often favorable impact on plant development (Solano et al, 2008), little is known about composition and functional activity of the orchid-associated bacteria and only one paper reported the occurrence of the N 2 fixing Azospirillum amazonense on roots of Brazilian orchids (Lange & Moreira, 2002).…”

Section: Introductionmentioning

confidence: 99%

Bactérias produtoras de auxinas isoladas de raízes de Cattleya walkeriana, orquídea Brasileira ameaçada de extinção, e sua função na aclimatização

Júnior

Pedrinho

Castellane

et al. 2011

Rev. Bras. Ciênc. Solo

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SUMMARYAuxin-producing bacteria inhabit the roots of orchids and can bring benefits to the host plant. Plants of this family are multiplied by in vitro assimbiotic conditions and little is known about the role of these microorganisms for ex vitro acclimatization. Four auxin-producing rhizobacteria isolated from the specie Cattleya walkeriana were evaluated for their ability to promote survival and growth of in vitro germinated plantlets during ex vitro acclimatization. Partial sequencing of the 16S rRNA genes of bacteria cultures from root velamen of this epiphytic species identified them as Bacillus, Burkholderia, Enterobacter and Curtobacterium. The presence of indole compounds in the filtered supernatants of liquid cultures was quantified by colorimetric assay and confirmed by HPLC. Indole-3-lactic acid (ILA) and indole-3-acetaldehyde (IAAld) were present in high quantities, except in Enterobacter sp. cultures, where in indole-3-acetic acid (IAA) and indole-3-pyruvic acid (IPA) were more prevalent. These rhizobacteria were inoculated into asymbiotically-germinated plantlets of the host orchid, acclimatized in greenhouse for 90 days and assessed for their growth-promoting ability. The lowest ability to promote growth was observed for Burkholderia sp. and Curtobacterium sp., while Bacillus sp. and Enterobacter sp. improved growth in all evaluated characteristics and increased the percentage of plantlet survival. This

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Detecção de Azospirillum amazonense em raízes e rizosfera de orchidaceae e de outras famílias vegetais

Cited by 9 publications

References 2 publications

Density and diversity of diazotrophic bacteria isolated from Amazonian soils using N-free semi-solid media

Density and diversity of diazotrophic bacteria isolated from Amazonian soils using N-free semi-solid media

Epífitas vasculares: histórico, participação taxonómica e aspectos relevantes, com ênfase na Mata Atlântica

Bactérias produtoras de auxinas isoladas de raízes de Cattleya walkeriana, orquídea Brasileira ameaçada de extinção, e sua função na aclimatização

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