Melhoramento genético do Eucalyptus para a biomassa florestal e carvão vegetal

Abstract

To help the establishment of strategies for a genetic breeding program for wood quality and charcoal, the objectives of the present study were: i) to estimate the phenotypical and genetic parameters for the wood characteristics and charcoal, ii) to estimate genetic gains in the selection process, iii) to select clones of Eucalyptus hybrids through wood characteristics and charcoal. Nine Eucalyptus clones, cultivated at the region of Taiobeiras, located at the North of Minas Gerais State were analysed. Three meters longs logs were utilized for specimens preparation. The experimental design used was the totally randomized, with three repetitions. From the expected mean square the phenotypical and genetic parameters were estimated. It was estimated the genetic gain for the characteristics that showed statistical significant differences. The effect of clone was significant for both the growth characteristics and mechanical properties of wood. Except for the volumetric shrinkage, the physical and chemical wood properties showed effect significant of clone. The effect of clone was significant for the fiber width and fiber walls tickness. For the charcoal characteristics, it was observed that the effect of clone was significant for charcoal yield, carbon yield and apparent relative density. The obtained genetic gains for both wood and charcoal changed from 4.16% for carbon yield to 27.58% for wood dry mass. The clones with higher number of favorable characteristics were the FGA-30, with emphasis on its growth characteristics, physical and chemical wood properties and charcoal yield; the clone FGA-49, with emphasis on the physical properties and clone I-380, with emphasis on the mechanical properties. Higher increments can be reached by the hibridization of these clones with others that presented higher growth rate. With the selection of the clones FGA-30 and FGA-34 it was predicted an increment of 53.44 m3 in the production of charcoal, corresponding to a predict additional income of R$4,007.95 for each hectare of planted forest.