Caracterização morfológica de micorrizas de Epidendrum secundum e Zygopetalum mackaii nativas do Parque Estadual da Serra do Brigadeiro (MG)

• Autor(a) principal: Linhares, Danielle Oliveira
• Data de Publicação: 2006
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/5333
• topic: Micorriza; Orquídeas; Biodiversidade; Epidendrum secundum; Zygopetalum mackaii; Mycorrhizae; Orchid; Biodiversity; Epidendrum secundum; Zygopetalum mackaii; CNPQ::CIENCIAS AGRARIAS::AGRONOMIA::FITOSSANIDADE::MICROBIOLOGIA AGRICOLA

Epidendrum secundum and Zygopetalum mackaii, native from State Park of Serra do Brigadeiro, Minas Gerais State, Brazil, were studied to characterize the structure of mycorrhizae and associated mycorrhizal fungi. From August/2004 to July/2005, roots were collected from four different areas. A total of 28 isolates were obtained, all belonging to genus Epulorhiza, which were separated in three groups according their morphological and cultural characteristics. In both orchid species, mycorrhizae were tolipophagic, and colonizing all extension of the root system, presenting intact and degraded pelotons. Root colonization occurs mainly through root hairs and sometimes via epidermic cells, while cortex colonization occurs, mainly, via passage cells of the exodermis. Cortex colonization occurs by cell-to cell, and pelotons occupy all cellular space. Peloton degradation starts by hypha deformation, followed by a uniform reduction of peloton volume. Colonization intensity was higher in the dry season. The species growing on rocks showed higher colonization frequency and higher mycotrophic activity. This is the first report on the mycorrhizal association of Z. mackaii. Isolated fungi in this study show high potential to be used in commercial propagation of this orchid species.