Genetic Study and Superior Provenance Selection of Loblolly Pine for Pulpwood Ⅱ. Indirect and Index Selection for Superior Provenance

The age-age correlation analyses of growth traits and wood property of 11 year old provenance test in Fuyang, Zhejiang showed that, 5～6 a was feasible and reliable minimum age to select loblolly pine pulpwood provenances in middle aged stand. In the same test, using indirect selection for stem volume and dry weight by growth traits ,the genetic gain were above 15% when the selection rate was 10%, and to select provenances for pulpwood based on appropriate selection index, the relative selection efficiency can reached above 60%. Selection indices were constructed for 4 provenance tests, and 10 high yielding and high quality provenances were selected, their average phenotypic and genetic gains of tree height were 6.94% and 4.59%,of tree diameter were 8.38% and 5.55%, of stem volume were 20.00% and 13.24%,of wood density were 1.63% and 1.08%, of stem dry weight were 24.78% and 16.40%.