Clone selection and application in the second generation seed-orchard of Pinus massoniana

114 clones were selected and 34 hm2 second generation seed-orchard of Pinus massoniana were built.By genetic test,according to the combination selection,among the full-sib families with medium heritability or more(0.5～0.8),the genetic gain of tree height,diameter at breast height and volume of the five-year-old stand were up to 8%～20.3%,13.6%～40.8% and 29.1%～74.7%,respectivey,and the ten-year-old ones reached up to 16.3%～39%,31.5%～44.4% and 58.7%～146.5%,respectively.The tree height,DBH and volume of the elite trees selected from the provenances and elite tree progeny test forest were higher than the control,with an increment by 4.9%～10.5%,1.6%～36.4% and 15.1%～115%,respectively.The clones in the seed-orchard grew well and fecundity was good.The tree height and DBH were up to 1.8～2.2 m and 2～5.5 cm,respectively,and 65.3% of the clones blossomed and seeded.The average height,DBH,crown width and ring branches of five-year-old grafted clones in the collective area were 4.4 m,6.2 cm,2.4 m and 5.3 circle respectively,and 90% clones blossomed and seeded.