Combining ability of elite clones of Eucalyptus grandis and Eucalyptus urophylla with Eucalyptus globulus

Abstract

In Brazil, eucalyptus breeding programs for cellulose production has used two species, Eucalyptus grandis and Eucalyptus urophylla. Nevertheless, it would be useful to introgress alleles from other species to improve wood quality and volume. The objective of this research was to evaluate the hybrid potential of elite clones of E. grandis and E. urophylla from the Aracruz Celulose Company S. A. with Eucalyptus globulus clones. To do so, six elite clones were crossed with ten E. globulus clones in a half-diallel mating design. The resulting hybrid combinations as well as the four check clones were evaluated in randomized complete block experiments with single plant plots and 40 replicates from September to October 2001 at three Brazilian sites, Aracruz and São Mateus in the Espírito Santo state and Caravelas in Bahia State. Two years later the circumference at breast height (CBH) and the wood density (WD) were measured. The means were submitted to diallel analysis according to the Griffing method (1956), adapted by Geraldi and Miranda Filho (1988). Although the number of clones involved was small, the crossings of elite clones of E. grandis and E. urophylla with clones of E. globulus were promising, especially for wood quality gains.

Xylem transcription profiles indicate potential metabolic responses for economically relevant characteristics of Eucalyptusspecies

“…In addition, the cellulose productivity of E. globulus is significantly higher than the average of other species; e.g., approximately 25% less wood is required to produce a ton of cellulose [7]. However, this species is not well adapted to tropical conditions [8] and is primarily cultivated in temperate countries such as Portugal, Spain and Uruguay.…”

Combining ability of tropical and temperate inbred lines of popcorn

“…Genitor discrepancies and good gene complementation is necessary to achieve favorable agronomic characteristics (Hallauer and Miranda Filho, 1995). Diallel analysis is a breeding strategy to obtain superior genotypes because it provides consistent results over the years (Amaral Júnior et al, 1999;Cavalcanti et al, 2000;Gouis et al, 2002;Silva et al, 2004;Jaramillo et al, 2005;Marin et al, 2006;Bison et al, 2007). In Brazil, many popcorn studies have been conducted to determine genetic divergence Dandolini et al, 2008;Vilela et al, 2008;Silva et al, 2009;Trindade et al, 2010) in conjunction with the additional efforts in cytogenetics (Ricci et al, 2007), seed quality (Moterle et al, 2008), agronomic responses (Vendruscolo et al, 2001;Scapim et al, 2010), plant pathology (Vieira et al, 2009a), and the evaluation of breeding methods (Rangel et al, 2007(Rangel et al, , 2008Arnhold et al, 2009;Freitas Júnior et al, 2009;Amaral Júnior et al, 2010).…”

Dialelo parcial entre clones de Eucalyptus camaldulensis e clones de E. urophylla, E. grandis e E. saligna

“…Resultados semelhantes foram relatados sobre o híbrido E. urophylla x E. pellita (BOUVET e VIGNERON, 1996). Em híbridos envolvendo progênies de E. grandis x E. urophylla foi constatado que a heterose média para CAP foi de 38,7% (BISON et al, 2006). Isso comprova que a variância de dominância contribui para a manifestação do caráter volume de madeira.…”

“…Esses resultados concordam com os obtidos neste trabalho. Resultados semelhantes foram obtidos por Bison et al (2007) em um dialelo parcial, conduzido nos mesmos locais, envolvendo os mesmos clones-elite com clones de E. globulus.…”