Interações entre micorriza arbuscular e rizobactérias em espécies leguminosas arbóreas nativas destinadas a reflorestamento

• Main Author: Gisele Milani Lovato
• Other Authors: Marco Antonio Nogueira
• Language: Portuguese
• Published: Universidade Estadual de Londrina. Centro de Ciências Biológicas. Programa de Pós-Graduação em Microbiologia 2006
• Online Access: http://www.bibliotecadigital.uel.br/document/?code=vtls000112597

Não informado pelo autor. === Many areas previously covered with native forests are abandoned due to decrease on soil fertility as consequence of soil degradation. Revegetation of degraded areas may be expensive due to costs involved in plantlets production, installation and fertilization. Thus, arbuscular mycorrhizal fungi (AMF) and rhizobacteria, not only N-fixing but also plant growth promoter, are good candidates to improve plant capacity to establish in degraded and low-fertility soils. Accordingly, the aim of this work was identify the most efficient interaction(s) between AMF (Glomus clarum, Glomus etunicatum, Glomus intraradices or Gigaspora margarita) and rhizobacteria on the plantlets productions of four woody leguminous trees (Enterolobium contortisiliquum, Peltophorum dubium, Anadenanthera colubrina and Parapiptadenia rigida) native from the Brazilian Atlantic Forest and employed in reforestation programs. The experimental design was entirely randomized in a 5x2 factorial arrangement (four AMF species and non-AMF control) with and without rhizobacteria in four replications, for each plant species and three harvesting time. The AMF species G. clarum and G. margarita improved all plant species growth and nodulation in two species, what generally coincided with a better P nutritional status. These most effective AMF also produced higher amounts of external hyphae. The double inoculation rhizobacteria-AMF increased plant height, and also N concentration and N accumulated in shoots in the most effective interactions. Rhizobacteria stimulated mycorrhizal root colonization in some plant species and was deleterious in others but had no effect on the external hyphae length. Effective microbial interactions improve the plantlet precocity, which can be transplanted earlier to the field. Nevertheless, an effective interaction between AMF and rhizobacteria depend on the host plant and also on the environment, what reinforces the need for previous screening to find the best plant-microbes interactions in order to be employed in reforestation programs.