Abstract:

The wood samples of 20 open-pollinated families taken from a 13-year-old progeny test of masson pine were used to study the genetics of wood chemical compositions including percentages of ash,pantosan,lignin,holocellulose,hot-water extractive and 1% NaOH extractive.The results showed that there were significant differences between families tested for wood chemical compositions,basic density and growth traits which were found to be under moderate or strong genetic control.Among 6 chemical components of wood,the heritabilities of contents of ash,pantosan and 1% NaOH extractive were higher than ones of content of lignin,holocellulose and hotwater extractive.The growth traits such as tree height,diameter at breast height and stem volume were significantly and negatively related to wood basic density and seemed to be independent of wood chemical components.Genetic correlations suggest that ash and hot-water extractive content could be good indicators to predicate percentage holocellulose and lignin respectively.The absolute differences between families for holocellulose and lignin content are small,however,i.e.2 to 3%,suggesting that it is impractical to breed for increased cellulose content through a selection program.The differences among individuals or clones can be utilized through vegetative propagation.

Key words: Masson pine, Wood chemical composition, Genetic control, Wood breeding