Genetic parameters and provenance variation of Pinus radiata D. Don. ‘Eldridge collection’ in Australia 2: wood properties

Abstract

Provenance variation and genetic parameters for wood properties of mature radiata pine (Pinus radiata D. Don) were studied by sampling three provenance/progeny trials in southeast Australia. Among the mainland provenances, Monterey and Año Nuevo had higher density and modulus of elasticity (at one site) than Cambria. Basic density and predicted modulus of elasticity (MoE) for the island provenances, Guadalupe and Cedros, were ∼20% higher at Billapaloola compared to mainland provenances grown at Green Hills and Salicki, differences that may or may not be linked to site differences. Heritability estimates of density, predicted MoE and microfibril angle were significant and ${\bar{h}^2}$ > 0.45, suggesting moderate to strong genetic control. The estimated genetic correlations between diameter at breast height and wood properties in the current study were weaker (less negative) than the mean estimated from the current breeding population generation in radiata pine. Of the wood properties, density showed the strongest adverse genetic correlations with growth (mean r _A  = −0.23 ± 0.09). Selection for MoE may produce greater gain than selection for density because MoE had almost twice the estimated additive genetic coefficient of variation (${\overline {\text{CV}}_A}$) compared to density. Estimated type B genetic correlations (r _B) for all wood quality traits were typically high, conforming to the trend that wood properties have low genotype-by-environment interaction (G × E). Significant differences in wood properties among provenances, families and/or individual trees provide an opportunity for breeding programmes to select superior trees for solid wood production that will combine superior growth with desirable wood traits.