华北落叶松优树半同胞家系的子代测定
Half-sib Progeny Test of Larix principis-rupprechtii Plus tree

Height and diameter at breast height and volume (with average experimental form-factor method）of 138 trees of half-sib progeny of north China larch (Larix principis-rupprechtii) occurring in Weichang County,Hebei Province were measured and calculated to select superior families and trees for advanced generation seed orchard.The results showed that there were significant differences among the half siblings of the larch,which indicated that the variation among the families was rich and had high potential in selective breeding.The heritability of tree height,diameter at breast height and volume were 0.368,0.447,and 0.429,respectively.Under the selection rate of 30%,41 superior families by volume were selected.Genetic gain of the superior families were 2.79% for height，6.99% for diameter at breast height,15.00% for volume