Genetic variation of chemical and mechanical traits of maritime pine (Pinus pinaster Aiton). Correlations with wood density components

Genetic selection for one trait can have an impact on other important traits for final use; thus, it is important to assess the correlation between traits. Genetic control and relationships among lignin content predicted by near infrared spectroscopy, radial modulus of elasticity (MOERad) and the radial modulus of rupture (MORRad), as well as its correlations with wood density components and spiral grain were assessed by estimating heritability, phenotypic and genetic correlations using 552 Pinus pinaster trees from 46 half-sib families. The results of this study showed that lignin amount is under a moderate genetic control (h(2) = 0.34) but due to the low coefficient of variation observed, selection for lignin content through breeding could yield modest gains. Selection based on density will result in a decrease of the lignin content, and that the lignin content was more dependent on the proportion of latewood. The results show that MOERad and MORRad are under moderate genetic control (h(2) = 0.34 and h(2) = 0.30 respectively), suggesting possible genetic gains by selection for higher resistance and elasticity. MOERad had higher correlations with latewood than earlywood components. Negative correlations were observed between mechanical traits and lignin content, while the correlations with spiral grain were positive.