Wood chemical composition, heat value genetic variation pattern and genetic parameter estimation for half-sib family of Castanopsis fissa in China

To study the wood chemical composition and heat value genetic variations of the half-sib family of Castanopsis fissa and estimate its genetic parameter, randomised complete block test method was adopted for the growth measurement, as well as wood density, cellulose content, lignin content and heat value analysis of the 6-year-old family. It was found that the wood densities of the half-rib family of Castanopsis fissa are in significant differences and the cellulose content, lignin content and heat value are in highly significant differences. The average wood density of 52 halfsib families of Castanopsis fissa is 0.4472 g/cm 3 and the genetic variation coefficient is 4.22% with a broad-sense heritability of 0.1916. The average wood cellulose content is 49.55% and the genetic variation coefficient is 6.41% with a broad-sense heritability of 0.2939, under weak genetic control. The average lignin content is 21.07% and the genetic variation coefficient is 5.17% with a broad-sense heritability of 0.4942, under weak and moderate genetic control. The average heat value of wood is 18680.11 J/g and the genetic variation coefficient is 7.16% with a broad-sense heritability of 0.7026, under strong genetic control. The DBH and height growth of the half-sib family of Castanopsis fissa are uncorrelated to the wood density, cellulose content or lignin content, but weakly correlated to heat value. It suggests that properties such as wood density, cellulose content and lignin content are mutually independent in terms of heredity. These properties can be selected independently to cultivate family with better wood properties.