Propriedades da madeira de Eucalypitus: classificação e seleção de genótipos utilizando marcador molecular e análise multivariada

Abstract

The attainment of sawn wood with superior qualfties is possible both by means ofjoint measures in the production process and by a genetic improvement and management program. Witha view to helping the estabüshment ofstrategies of a genetic breeding program of wood quality, the present aimed to: 1) classify and select genotypes ofEucalyptus by means of its technological propertíes by utilizing the grouping analysis by Tocher's optimization method; 2) classify Eucalyptus genotypesfor the valuationofwood qualityafter natural drying and identification of those ofsuperior quality; 3) evaluate the utilization ofRAPD markers for detection and maximizing the genetic variabihty in eucalyptus genotypes, coming from the northwestern region ofMinas Gerais. According to the results, it may be concluded that the analysis of grouping obtained by utilizing the mechanic, physical and chemical characteristics classifled the genotypes into 11 distinct groups with possibihties of obtaining multiple uses. For the evaluation of wood post - drying were utilized three quality classes and through the mscriminating analysis the allocation ofthe genotypes within their classes was checked and corrected. The total sum of defects for classes I, II and Iii was, respectívely, 6.57%, 16.57% and 28.34%, classes I and III presenting superior losses, I of 152.2% and 331%, respectively and class III presented 71% ofloss more relative to class II. The RAPD molecular markers presented efficient discrimination power among the 44 genotypes evaluated, an average genetic distance among the eucalyptus genotypes of54%with a genetic divergence ranging from 24 to 73% being found. that points out that amongthe analyzed individuais, there are more promising genotypes to increasethe genetic basis ofthe material.