Growth and wood density of 25-year-old Masson's pine: inter-family variation and selection.

25-year-old Masson's pine(Pinus massoniana) trials including 46 open-pollinated families located at Hua'an county in Fujian province were used to reveal the variation among families in growth,stem-form qualities and wood basic density,and select superior families suitable for producing pulp wood and building timber,respectively.The results indicated that there existed significant differences among families in growth,stem fullness and wood basic density.The variation was relative larger for growth and stem straightness than the other traits.The coefficients of variation of stem fullness and wood basic density were below 10%.It was found that growth,stem form and wood basic density were under moderate to weak family genetic control,and family heritability ranged from 0.23 to 0.46.Among test traits,the family heritability of wood basic density was the largest which reached 0.46.Genetic correlation suggested that the stem fullness could be concurrently improved by selecting the fast-growing families.However,the wood basic density and stem straightness were not influenced by growth.24 and 6 superior families were selected for pulpwood and sawn timber,respectively.Both of the mean wood dry matter accumulation and DBH growth were 1.16 times that of the control.