Study on Provenance Selection of Loblolly Pine for Construction Timber

The results of study on the 10 a loblolly pine provenance test in Fuyang City of Zhejiang Province showed that the distinct differences in main traits relating to the provenance evaluation of construction timber existed among provenances in juvenile wood stage,the phenotypic variation coefficients of growth traits were 10%～30%,of traits of wood physic-mechanical properties and tracheid morphological features were about 5%,all of these traits were genetically controlled with above moderate broad sense heritabilities,the simple phenotypic correlations between growth traits and wood property traits were weak. The results of multitrait selection using preliminary index showed provenances of RL31,RL26,RL30,RL22,CL8 were good for construction timber,their average genetic gains of stem volume,wood density,crushing strength,modulus of elasticity were 5.96%,5.44%,3.17%,4.87% respectively compared with the average value of the test stand.