Analysis of growth performance of different families of Toona ciliata at seedling stage and young forest stage in Jianghan plain

Toona ciliata is an important local species in Hubei province, but it has not been naturally distributed and artificially cultivated in the Jianghan plain. In order to select superior families of T. ciliata which are suitable for the Jianghan plain area, and to provide valuable timber tree species afforestation resources for this area.

A comparative afforestation experiment was carried out in Shishou city, which was located in the Jianghan plain, using a randomized block design for 17 T. ciliata superior half-sib families from Enshi area in Hubei province to compare the 2-year seedling stage and 2-year young forest stage, and to carry out the early selection of superior families by analyzing and comparing the characteristics of DBH (the ground diameter was measured in the first year), tree height and volume of different families for 4 consecutive years.

There were significant differences in DBH(ground diameter) and tree height traits among different families at all ages. All DBH and tree height traits in the following 3 years were significantly correlated with each other from the second year of seedling stage. The family heritability of DBH, tree height and volume traits exceeded 0.85 from 2020 to 2022. According to the genetic gain of different traits of different families, mainly by volume gain, 3 families with excellent early performance were selected from 17 families, namely E13, E15 and E06 families, with the selection intensity 17.65%.

3 families with excellent early performance were selected from 17 T. ciliata superior half-sib families, whose volume genetic gain exceeded 20% of the population average, with high selection intensity and obvious early growth advantage. The average annual DBH was 2.09 cm and annual tree height was 1.78 m. These families will become important germplasm resources for breeding of improved varieties of T. ciliata in Jianghan plain, Hubei province.