Genetic variations and selection of diallel progenies in the second generation of seed orchard of Chinese fir

Genetic variations of growth and wood quality traits among families in different ages were studied and the superior families and trees were selected using diallel progeny test which was established at yangkou nation forest farm in Fujian province with the 10 fastest growing clones as parents which were from the second seed orchard of Chinese fir. The results showed that there were large genetic variations among families in different ages. Differences of tree height,DBH and volume were very significant among families. Genetic variation coefficients of red-colored heartwood,eccentricity,bark and basic density were large,and there were large genetic variations among families,wood quality traits were improved with age. 5 superior families were selected in tree volume and wood basic density,and the average genetic gain were 6. 08% and 3. 85% compared with the control,respectively. Fast growth and good wood quality families could add to garden group as genetic materials of high generation of Chinese fir to promote the use of the seed orchard construction. 12 superior trees were selected on the basis of family selection,and the average genetic gain reached to38. 24% compared with the control. The obviously yield increasing effect showed that these trees could not only be the ideal material of high generation breeding but also to be used through asexual reproduction.