Selection ofCorymbia citriodorafor pulp productivity

Abstract

10Evaluation of a series of spotted gum (Corymbia citirodora) progeny trials, 11 established in the subtropical region of Queensland, Australia, was undertaken to 12 provide information for the development of advanced generation breeding 13 populations suitable for pulp production. Measurements of growth at two ages were 14 combined with assessments of wood density and pulp yield from a selected sample 15 of provenances to provide comparisons between provenances, to generate genetic 16 parameter estimates and to predict genetic gain potential. While growth at this age 17 was moderate relative to other eucalypts the near infrared predictions of average 18 wood density of 756 kg/m 3 and pulp yield of 55% indicate the species has 19 considerable potential as a pulpwood crop. A pulp productivity breeding objective 20 was used to identify production populations using a range of selection trait 21 weightings to determine potential genetic gain for pulp productivity. Genetic 22 parameters indicated: 1) levels of genetic control were moderate for all traits and 23 higher for wood property traits, 2) genetic improvements could be achieved by 24 selection among and within provenances with greater levels of improvement 25 available from selection within populations, 3) genotype by environment interactions 26 were negligible, 4) genetic correlations between traits were favourable, and 5) 27 selection of volume production alone would maximise improvements in pulp 28 productivity. 29

Challenges in the use of Near Infrared Spectroscopy for improving wood quality: A review

“…They pointed out that wood chemistry traits were genetically inter-correlated (e.g., negatively between lignin and cellulose), whereas correlations with growth were not significant, indicating that growth and chemical properties could be improved independently. Brawner et al (2012) evaluated a series of spotted gum (Corymbia citriodora) progeny trials in Queensland, Australia for generating genetic parameter estimates and to predict genetic gain for pulp production. They pointed out that the NIR based predictions of average wood density and pulp yield indicate the species has considerable potential as a pulpwood crop.…”

Sobrevivência e crescimento inicial de espécies de eucalipto em diferentes condições climáticas

“…No Brasil o híbrido de Corymbia mais difundido é C. torelliana x C. citriodora, sendo que os resultados obtidos neste trabalho corroboram com estudos realizados na Austrália que destacam C. henryi e C. citriodora variegata com bom potencial para hibridação (LEE et al, 2007;2005). A hibridação entre espécies do gênero Corymbia é uma das opções para minimizar o efeito dos estresses (ASSIS, 2015) e é de interesse para a produção de celulose a partir de matéria prima com alta densidade (BRAWNER et al, 2012).…”

NIR for combined selection in hardwoods for both growth and wood properties

“…The quality of timber obtained from plantation-grown CCV is suitable for most purposes (Harding et al 2009b;Washusen et al 2009), and exceeds industry standards for many products (Huth et al 2012). In addition, the species has high pulp yield and wood density so it can be well suited for pulpwood production (Clark & Hicks 2003;Brawner et al 2012). To support the developing plantation program with CCV, there is a need to quickly develop genetically improved planting stock, and to optimise breeding efforts to improve the growth and wood properties of CCV.…”

“…Although initial growth is relatively slow compared to many eucalypts, CCV maintains its early growth rate and can withstand or recover quickly from difficult environmental conditions such that post-planting survival is typically high (Clarke et al 2009). Further, the sawn timber of CCV attracts a price premium in Australia, and is also suitable for pulpwood products Brawner et al 2012). Genetic improvement of CCV for both pulp and solid-wood products in north-eastern Australia is being undertaken to improve the growth and wood properties in order to support the development of economically viable plantation forestry in this region (Lee 2007;Smith et al 2007;Brawner et al 2012).…”

“…While KPY and DEN of eucalypts have been a focus of several studies (e.g. Gardner et al 2007;Lee et al 2011;Brawner et al 2012), little has been published for either MOE or MfA. Lee (2007), Lee et al (2009), Johnson et al (2009 have reported on tree-improvement activities and genetic control of key traits in the spotted gums.…”