Genetic variation in wood density of triploid clones of Populus tomentosa.
Xing Xinting;Zhang Zhiyi.Institute of Populus tomentosa, Beijing For. Univ.,100083,P.R.China.
The genetic variation in wood densities of triploid clones of Populus tomentosa Carr. were investigated and the variations in wood densities among clones, radial direction and vertical direction were studied in this paper. The average values of growth ring densities, early wood densities, late wood densities were 0 444,0 428,0 511 g/cm 3 respectitively. There were significant differences among clones and among growth rings in wood densities.The radial direction variation in wood densities were unstably accending, the vertical variation patterns were not identical.Clonal repeatabilities of growth ring densities, early wood densities, late wood densities of air dry timber were 0 89, 0 92 and 0 86 respectitively.This indicated wood densities were under strong genetic controls.