Abstract: A total of 49 open-pollinated families of Masson pine (Pinus massoniana) collected from plus trees of natural forests were used to test the resin-tapping capacity for 6 years.Results showed that the resin-yielding capacity (RYC) increased rapidly at early ages and maintained at a stable level after age 13 a. Variance analysis detected plenty of genetic variations in RYC among families. Additive genetic coefficients of variations (CV) showed a decreasing RYC trend with ages. The genetic variations were under middle-level genetic control. Heritability also showed a decreasing trend with ages, and family heritability was apparently higher than individual heritability. There were close positive genetic correlations in RYC between early and mature ages,and the correlations displayed an increasing trend with ages. Early selection at age 11 a was highly effective since the efficiency reached 0.813. A selection based on comprehensive breeding values screened out 13 superior families whose breeding values (BVs) were much higher than that of control and displayed an increasing trend with ages.

Key words: Pinus massoniana, open-pollinated families, resin-yielding capacity, early selection, breeding value