Caracterização anatómica da casca de Eucalyptus nitens (Deane & Maiden) e Eucalyptus rudis Endl. para identificação das espécies

• Author(s): Patrício, Helena Sofia Maurício
• Date: 2014
• Persistent ID: http://hdl.handle.net/10400.5/6800
• Origin: Repositório da UTL
• Subject(s): Eucalyptus nitens; Eucalyptus rudis; bark; anatomy; cell dimensions; cell type proportions
• Document Type: Master thesis
• Language: Portuguese
• Advisor(s): Pereira, Helena Margarida Nunes; Santos, Teresa Quilhó Marques dos
• Contributor(s): Repositório da Universidade de Lisboa

Description

Mestrado em Engenharia Florestal e dos Recursos Naturais - Instituto Superior de Agronomia

The bark of 5 trees of E. nitens with 4 and 10 years of age, and 5 trees of E. rudis with 4 years of age was analyzed. The qualitative characterization and the determination of the tissue proportions were made on histological thin sections and quantitative characterization on dissociated elements; the dimension of fibres, axial parenchyma and expanded cells was also determined. The species showed: reduced rhytidome, periderm composed by phellem with suberised and lignified cells and phelloderm; non-collapsed phloem with tangential layers with axial parenchyma alternating with sieve tube elements and fibre bundles; the collapsed phloem is characterized by the change of the parenchyma cells and sclereids. The length, width and wall thickness of fibers was in 4-year-old E. nitens 0.90 mm; 16.2 μm and 4.7 μm; in 10-year-old E. nitens 1.05 mm; 17.8 μm and 5.2 μm and E. rudis 0.84 mm; 21 μm and 6 μm respectively. The expanded axial parenchyma cells are the most abundant phloem tissue (38-48%) in both species; the percentage of fibers was higher in E. nitens (33%). The species differed in the type of periderm, in the arrangement of the expanded cells and in the occurrence of secretory cavities.