Bactérias endofíticas promotoras de crescimento de plantas em mudas de pupunheira

The objective of this work was to isolate endophytic bacteria from peach palm (Bactris gasipaes var. gasipaes) plants and to evaluate the effects of their inoculation on the plant seedlings. Bacteria were isolated from the leaves and roots of the seedlings and from the meristems of peach palm plants in vitro. The isolates were characterized phenotypically and, then, 15 of them, representing different phenotypic groups, were selected and identified by partial sequencing of the 16S rRNA gene. Afterward, these isolates and two commercial strains of Azospirillum brasilense (Ab-V5 and Ab-V6) were inoculated in the peach palm seedlings. After 76 days, the seedlings were evaluated for plant development. The following six genera were identified based on the sequencing: Pseudomonas, Enterobacter, Rhizobium, Stenotrophomonas, Klebsiella, and Erwinia. Out of the 15 inoculated isolates, 9 had a positive effect on the root dry mass of palm peach, with CNPF 77 (Enterobacter sp.), CNPF 100 (Rhizobium sp.), and CNP 179 and CNPF 277 (Stenotrophomonas sp.) standing out. Peach palm seedlings harbor endophytic bacteria which are able to increase root dry matter.O objetivo deste trabalho foi isolar bactérias endofíticas de pupunheira (Bactris gasipaes var. gasipaes) e avaliar os efeitos da inoculação delas em mudas da planta. As bactérias foram isoladas de folhas e raízes das mudas e de meristemas de pupunheira in vitro. Os isolados foram caracterizados fenotipicamente, e, depois, 15 deles, representando grupos fenotípicos distintos, foram selecionados e identificados por meio do sequenciamento parcial do gene 16S rRNA. Em seguida, esses isolados e duas estirpes comerciais de Azospirillum brasilense (Ab-V5 e Ab-V6) foram inoculados em plântulas de pupunheira. Após 76 dias, as mudas foram avaliadas quanto ao desenvolvimento vegetal. Foram identificados os seis seguintes gêneros com base no sequenciamento: Pseudomonas, Enterobacter, Rhizobium, Stenotrophomonas, Klebsiella e Erwinia. Dos 15 isolados inoculados, 9 tiveram efeito positivo sobre a massa de matéria seca de raízes, com destaque para CNPF 77 (Enterobacter sp.), CNPF 100 (Rhizobium sp.), e CNP 179 e CNPF 277 (Stenotrophomonas sp.). Mudas de pupunheira abrigam bactérias endofíticas capazes de aumentar a matéria seca das raízes