Genetic variation for growth and selection in adult plants of Eucalyptus badjensis

Abstract

The aim of this study was to evaluate Eucalyptus badjensis concerning the genetic variation for growth traits and the potential of the species in supporting a breeding programme. The field trial was a provenance/progeny test established in Campina da Alegria, Santa Catarina, Brazil (latitude 26°52′05.1″ S, longitude 51°48′47.5″ W, altitude 1,015 m) in a soil classified as Latossolic Alumino-Ferric Brown Nitosol. The experiment comprised 60 open-pollinated progenies from the provenances Glenbog and Badja State Forest, New South Wales, Australia. Ten replicates and plots with six plants in row were used. At the age of 17 years, 279 trees were assessed for diameter of the bole at breast height (DBH), total tree height (H) and volume of wood with bark (Vol). After submitting the data to statistical genetic analysis, the overall means for DBH, H and Vol were 45.17 cm, 33.30 m and 2.84 m3, and the estimates of additive coefficient of variation [CV^a(%)] were 12.59%, 5.91% and 26.51%, respectively. Heritability coefficients of additive effects (trueh^a2) were also estimated and the following values were found: 0.443, 0.312 and 0.358. Thirty-nine trees from 25 different progenies were selected. The expected means of the provenances after improvement were 50.02 cm, 34.35 m and 3.47 m3 for DBH, H and Vol, respectively.

Desempenho de espécies de Eucalyptus para uso em sistemas de integração floresta-pecuária no bioma Pampa

“…E. benthamii é considerada mais tolerante a geadas do que E. dunnii e apresenta como vantagens a disponibilidade de sementes e de mudas de clones para plantios comerciais. E. badjensis também é considerado uma alternativa para plantios na região Sul do Brasil, além de E. dunnii e E. benthamii, principalmente em função da tolerância a geadas (Paludzyszyn Filho et al, 2006;Santos et al, 2015). Entretanto, essas espécies, nas condições experimentais de campo, não apresentaram bons desempenhos em termos de percentuais de sobrevivência e crescimento.…”

“…Com relação às opções de germoplasmas que reúnem as características de tolerância ao frio e à seca, viabilidade de propagação clonal e múltiplos usos da madeira, um número muito pequeno de alternativas para plantação está disponível em regiões propensas a eventos climáticos de forte intensidade (Moraes et al, 2015;Santos et al, 2015).…”

“…Dentre as espécies de eucalipto economicamente importantes para as condições climáticas da Região Sul do Brasil, e que apresentam boa aptidão para produção de madeira para fins energéticos e também para serraria, a Embrapa Florestas tem desenvolvido pesquisas prioritariamente com as espécies Eucalyptus dunnii, E. benthamii, E. badjensis, E. grandis e E. saligna (Paludzyszyn Filho et al, 2006;Moraes et al, 2015;Santos et al, 2015), sendo as três primeiras as mais indicadas para regiões mais propensas a geadas severas (latitudes entre os paralelos 24° e 32° S) (Santos et al, 2015).…”

GENETIC VARIATION FOR GROWTH VARIABLES OF Eucalyptus benthamii MAIDEN & CAMBAGE AND E. smithii R. T. BAKER PROVENANCES IN SOUTHERN BRAZIL

“…Our evaluation showed the and POTTS, 2008). Progenies of distinct provenances of E. badjensis revealed heritabilities of 0.44, 0.31 and 0.358, respectively for DBH, H and VOL (SANTOS et al, 2015). The evaluation of 30 clones of E. globulus showed heritability of 0.37 for diameter of the basal region of the trunk, 0.6 for H and 0.12 for VOL (SCHMIT et al, 2015).…”

“…To circumvent environmental issues as well as introducing new genetic variability, alternative eucalypt species have been tested in different locations in Brazil and other countries (ALMEIDA-AZEVEDO et al, 2015;SANTOS et al, 2015;COSTA et al, 2016;ENGEL et al, 2016). Whether as single species or hybrid combinations, considering the natural proclivity for hybridization among determined taxa of Eucalyptus or Corymbia, plantations of alternative species are accounting for the total area of eucalypts produced (IBÁ, 2016).…”