Strong Genetic Control of High Wood Specific Gravity in Young Progenies of Pinus brutia: Potential of Early Selection for Industrial Plantations

To increase quality and amount of wood production in Turkish red pine (Pinus brutia Ten.), genetic control of wood specific gravity (WSG), tracheid length and growth traits was investigated in Ceyhan1A progeny trial by evaluating 168 families originated from six clonal Turkish red pine seed orchards. Wood samples were taken by destructive sampling during the rouging of this trial at the age of seven. Differences among the 168 families for mean WSG was large (ranged from 0.35 to 0.62), as indicated by high individual (0.42±0.07) and family mean (0.55±0.03) heritabilities. Family differences and high heritabilities were also observed for all growth traits and tracheid length. Genetic correlations between WSG and growth traits were insignificant (near zero), while low and insignificant negative phenotypic correlations among the same traits were also observed. Predicted genetic gain for single trait selection at age of seven was low for WSG (0.37%), but substantial for stem volume (8.4%) in phenotypic seed orchards. However, the first generation clonal seed orchards consisting of the best 30 clones yielded higher genetic gains (5.2% for WSG and 35% for stem volume). These preliminary results suggest that selection for wood characteristics and growth traits in Turkish pine could be practiced at early ages for short rotation (about 30 years) in industrial plantations.