Jupiter Israel Muro Abad

Parâmetros quantitativos da anatomia da madeira de eucalípto que cresceu em diferentes locais

It is known the influence of the growth place in the properties of the woods and that they are affected mainly by the anatomical structures. The objective of this work was to evaluate the quantitative parameters of the anatomical structure of the eucalypt wood of one clone of the natural hybrid of Eucalyptus grandis at 64 months of age occuring in Rio Claro, state of Sao Paulo. The 138 trees were grown in Aracruz, Domingos Martins, Alto Rio Novo, Sao Mateus in the state of Espirito Santo and in Mutum and Aimores in the state of Minas Gerais. The anatomical parameters measured were diameter and vessel frequency, length, fiber and diameter of the fiber, fiber wall thickness and width, height and frequency of the rays. According to the results, it can be concluded that, in relation to the vessels, there were significant differences among all regions. It was also observed significant differences in the parameters related to the rays in all regions. The wood produced in the Aracruz region had fibers with length and wall thickness with a much lower quality than the wood in the other studied regions.

Comparison of Sample Preparation Methods for NIR Analysis of Carbohydrate Content of Unbleached Eucalyptus Pulps

Abstract Near-infrared (NIR) spectroscopy provides a rapid method for estimating pulp carbohydrate content. Previous studies have used a variety of sample preparation methods; however, the influence of preparation method on calibration performance has not been examined. This study compares carbohydrate content calibrations for four sample preparation methods (coarse, fine, and milled pulp, and handsheets). Fifty-nine unbleached pulps (52 single-tree, 7 mill composite) with known carbohydrate composition (arabinose, fructose, galactose, glucose, rhamnose, and xylose) were prepared using the four methods. NIR spectra were collected from the samples, which were divided into calibration (40 samples) and prediction sets (19 samples). Calibrations were created for each combination of preparation method and carbohydrate, and tested on the prediction set. Calibration statistics were good for rhamnose and xylose but weaker for other carbohydrates. Coarse and fine pulp produced the best calibrations, but they were not significantly different from calibrations for handsheets; milled pulp provided the weakest calibrations.

Development of near infrared calibrations for physical and mechanical properties of eucalypt pulps of mill-line origin

Near infrared (NIR) spectroscopy has been used in several studies to predict the physical and mechanical properties of pulp hand-sheets. In most of these studies, wood samples were pulped in a laboratory under different regimes and/or refined to introduce variability into the data set. This study investigates the potential of NIR spectroscopy to create calibrations for eucalyptus pulp properties of mill-line origin. Seven mechanical properties (air resistance, compressibility, drainability, hygro-expansivity, stretch, tensile index and tensile stiffness) and three physical properties (bulk density, specific volume, and surface area) were investigated. Coefficients of deter mination (R2) for all 10 properties were poor. The R2C value exceeded 0.70 for only one property (tensile index), while the R2CV values exceeded 0.40 for only two properties (drainability and surface area). Ratios of performance to deviation were equally poor, ranging from 0.87 for bulk density to 1.28 for drainability. These statistics indicate that none of the calibrations could be used to accurately predict the properties of unknown samples. The poor performance of the calibrations is likely due to the low variability of our dataset, which is generally inherent in samples of mill-line origin.

Evaluation of the genetic diversity of a set of parents of Eucalyptus spp. by using microsatellite markers to direct matings

Background To obtain genetically superior cultivars in a breeding program, methods and procedures are necessary to allow the identification of selected individuals over several cycles of selection while at the same time maintain broad genetic base of the breeding populations. This is crucial to guarantee continuous genetic gains along the program. The establishment of efficient breeding strategies depends on methods and analytical tools. The assessment of genetic diversity with molecular markers of parents used in mating designs could aid optimizing the recombination phase. Microsatellites provide good information content and require small amounts of DNA and may be transferable between species of the same genus. In this study we evaluated the genetic diversity in a set of Eucalyptus parent trees and indicated those to be preferentially crossed in a recombination process to potentially maximize variation in the offspring for individual selection of clones.