Abstract: In order to evaluate and select superior germplasm of Pinus koraiensis, with the 28-year-old 53 half-sib P. koraiensis families in Sanchazi forestry bureau, Jilin Province as materials, we measured the growth traits(tree height, basal diameter, diameter at breast height, diameter at 3 m, tree height under the first branch and tree height under the sixth branch) and shape traits(branch angle, stem straightness degree and branch number per node). Variance analysis showed that except for some of the shape traits, most of the growth traits showed strongly significant differences among the sources of variation(P<0.01). The phenotypic coefficient of variation of all the traits ranged in 6.97%-37.39%. The genotypic coefficient of variation of all the traits ranged in 1.76%-26.75%; The family heredity of all the traits ranged from 0.031-0.827; The single heredity of all the traits ranged in 0.019-0.864, lower heritability of a few traits. Correlation analysis results showed that there were significantly positive correlations(r>0.073) of the most traits except for branch angle. The results of general combining ability analysis showed that the families with high general combining ability of different traits had great differences, which was difficult to carry out combined screening and further analysis was needed. The results of principal component analysis showed that the cumulative contribution of the three principal components was 72.31%, which indicated that the three principal components contained most information of the growth and shape traits of the tested families. Tree height, basal diameter, diameter at breast height, diameter at 3 m height and volume contributed greatly to principal component Ⅰ, and described the growth characters of P. koraiensis, so it can be used as an evaluation index for selecting excellent families. Selection of family and single plant by multiple-trait comprehensive evaluation, based on the real gain of family volume over 35%, 5 excellent families were selected, and the selection rate was 10%, average tree height, basal diameter, diameter at breast height, diameter at 3 m height and volume were 7.90 m, 25.02 cm, 19.21 cm, 16.23 cm and 0.107 4 kg·m^-3, and the real gains were 3.94%, 14.71%, 17.26%, 19.34% and 39.48%, respectively. Selecting single plants within the excellent families, according to the standard of genetic gain over 100% of single plant volume, 6 excellent individual plants were selected, and the selection rate was 4%, the tree height, basal diameter, diameter at breast height, diameter at 3 m height and volume mean values of the single plants were 1.60 m, 8.54 cm, 7.04 cm, 6.69 cm and 0.097 kg·m^-3 higher than the total average, and the genetic gains were 5.99%, 29.92%, 35.53%, 37.06% and 102.04%, respectively. The selected excellent families and individuals can provide the basis for validation of improved varieties and provide materials for the construction or reconstruction of the orchard.

Key words: Pinus koraiensis, half-sib families, growth traits, genetic gains, family selection, individual selection