Microrganismos endofíticos de mandioca de áreas comerciais e etnovariedades em três estados brasileiros

Abstract

Resumo -O objetivo deste trabalho foi realizar um levantamento da diversidade de microrganismos endofíticos, em plantas de mandioca (Manihot esculenta Crantz) coletadas de áreas comerciais, no Estado de São Paulo, e de etnovariedades dos estados do Amazonas e Bahia e, também, avaliar seu potencial para fixar N atmosférico e para produzir ácido indolacético. Nos três estados, foram identificadas 47 espécies de microrganismos pertencentes a 27 gêneros. Bacillus spp. foi o mais freqüente em todas as regiões. O maior número de gêneros foi encontrado em plantas provenientes do Estado do Amazonas, que apresenta a maior diversidade de microrganismos endofíticos. Amplificações por PCR do gene nifH foram avaliadas em espécies bacterianas pertencentes às γ-Proteobacteria. Isolados AIA positivos foram obtidos de material coletado em todos os estados, e foram representados por microrganismos pertencentes aos subgrupos γ-Proteobacteria, β-Proteobacteria, Bacilli e Actinobacteria. A ocorrência de bactérias endofíticas em plantas de mandioca, com capacidade para fixar N atmosférico e produzir AIA in vitro, indica potencial para promover o crescimento da planta.Termos para indexação: Manihot esculenta, Bacillus, Actinobacteria, fixação de nitrogênio, ácido indolacético. Cassava endophytic microorganisms of commercial plantings and ethnovarieties in three Brazilian statesAbstract -The aim of this work was to perform a survey of the diversity of endophytic microorganisms in cassava (Manihot esculenta Crantz) collected from commercial plantings, in the State of São Paulo, and in ethnovarieties collected in the States of Amazonas and Bahia, and also, to evaluate its potential of biological nitrogen fixation, and to produce indolacetic acid. In those States, 47 species of 27 genera were identified. Bacillus spp. was the most frequently found in all sampled regions. In Amazonas State, it was found the higher diversity of endophytic microorganisms. PCR amplifications of the nifH gene were evaluated in species of γ-Proteobacteria subgroup. IAA production was found in microorganisms isolated in cassava grown in all sampled States and belonged to the following subgroups: γ-Proteobacteria, β-Proteobacteria, Bacilli and Actinobacteria. In cassava, the occurrence of endophytic bacteria, with N-fixing and in vitro IAA-producing abilities, indicates potential for plant growth promotion.Index terms: Manihot esculenta, Bacillus, Actinobacteria, nitrogen fixation, indol-acetic acid. IntroduçãoOs microrganismos associados às plantas são considerados endofíticos, quando habitam o interior da planta sem causar danos aparentes ao hospedeiro (Hallmann et al., 1997

Molecular phylogeny and biotechnological potential of bacterial endophytes associated with Malpighia emarginata

“…In their research on the isolation and identification of endophytic bacteria of cassava from three Brazilian States (São Paulo, Amazonas, and Bahia), Teixeira et al, (2007) listed 27 genera, with the most frequent being Bacillus, Burkholderia, Enterobacter, Escherichia, Salmonella, Stenotrophomonas, and Serratia. West et al (2010) isolated endophytic bacteria from several tissues of grapevine including the stem, root, and leaves.…”

Bioprospection and genetic diversity of endophytic bacteria associated with cassava plant

“…This fact may be related, among other factors, to the close relationship between the crop and plant growth promoting bacteria (TEIXEIRA; MELO;VIEIRA, 2005). Thus, studies that evaluate the association of this plant with these microorganisms have become important, since they are used in the management of this crop.…”

Use of PCR-DHPLC with fluorescence detection for the characterization of the bacterial diversity during cassava (Manihot esculenta crantz) fermentation

“…Endophytic microorganisms are important in agriculture and are regarded to be ubiquitous, i.e., they are found in virtually all cultivable plants including soy (Hung et al, 2007;Li et al, 2008), beans (Trujillo-López et al, 2006), corn (Rijavec et al, 2007), cassava (Teixeira et al, 2007), potato (Rasche et al, 2009), rice (Mattos et al, 2008), and peanut (Ibáñez et al, 2009). Cassava (Manihot esculenta Crantz) storage roots have been widely used for human and animal nutrition, mainly in tropical regions.…”

“…Industrial processing of cassava results in a number of products such as distilled beverages and biofuels (Choi et al, 2010;Zhang et al, 2010). Like other agronomic crops, cassava may be colonized by different soil microorganisms, such as mycorrhizal fungi and diazotrophic bacteria (Balota et al, 1999;Teixeira et al, 2007).…”