Abstract
Genetic parameters of a control pollination family in Cryptomeria japonica in respect to fundamental indicators of wood quality (specific gravity at sapwood and heartwood, moisture content at sapwood and heartwood and Young's modulus) and diameter at breast height was evaluated by thinning a 17 year-old progeny test plantation (3 replica-tions, 21 combinations). Variance-covariance analysis was conducted as factorial mating and narrow sense heritability and phenotypic and genetic correlations were calculated. ANOVA showed that there were significant differences among female and male adults in most characteristics of wood quality but only in Young's modulus among replica-tion x combination and female x male adults. Narrow sense heritability showed around 0.2 on the specific gravity at sapwood and heartwood and Young's modulus but showed low values on moisture content. Genetic correlation was more closely related between almost all characteristics than phenotypic correlation. However, this fact did not always indicate that improvement of a single characteristic improved other characteristics. These results suggested that although each characteristic of wood quality could be improved, the selection method must be considered to improve wood quality comprehensively.
