Selection of superior families of Pinus massoniana in southern China for large-diameter construction timber

This study addresses the increasing demand for large-diameter production timber, and considers the time and space variability of half-sib families of Pinus massoniana . Height, diameter at breast height (DBH) and timber volume of 440 open-pollinated half-sib progeny families were investigated in 14 progeny trials in different years and production regions. An evaluation of the genetic variation of all half-sib families was carried out during the sustainable rapid growth period and individual volumes were characterized as a major index. ANOVA analysis showed that there was considerable variance in the growth traits of most families in different years and on different sites. The variations caused by temporal and spatial changes of the mating system required three selection methods for analysis. The results show that there were differences among the heritabilities of different growth traits by different half-sib progenies. Average heritability values of height, DBH and volume were 0.33, 0.34 and 0.36, respectively. Forty-five superior families were selected in every progeny test, 12 were selected in progeny trials by different years and five in different habitat progeny trials. Three superior families (Gui GC553A, Gui GC414A and Gui GC431A) were selected, although in different years and production regions. The genetic gains of timber volume of these selected r families ranged from 1.20 to 47.00%, which could provide a foundation for superior wood property selection and serve as material for seed improvement and extension in surrounding areas.