Analysis of genetic parameters of growth and wood traits provides insight into the genetic improvement of Schima superba

Schima superba (Theaceae) is widely distributed in subtropical China, and is the main timber and ecological afforestation tree species. This study aimed to provide a practical basis for the genetic improvement of wood traits of Schima superba. Herein, 10-year-old, half-sib families S. superba trees were used to reveal the genetic variation and control of growth traits and wood traits, as well as the correlation between them. The results revealed significant differences in tree height, DBH, and wood basic density among families. Furthermore, the differences in wood anatomical traits between families increased with age. The order of phenotype and genetic variation among families from large to small was DBH, tree height, vessel, fiber, and wood basic density. The phenotype variation and genetic variation of wood anatomical traits also increased with age. Heritability estimates revealed that wood basic density, DBH, and tree height were under stronger genetic control; fiber and vessel were under moderate genetic control. The correlation results showed that tree height, DBH, and wood basic density could be selected independently. Wood basic density and wood anatomical traits together could be improved. Moreover, based on the selection traits of DBH and WBD, families with excellent growth and wood traits were selected using breeding values.