Abstract:

To provide reference for the selection of fine families at seedling stage and the subsequent breeding of improved varieties, twenty one half sib Toona ciliata families from 5 regions in Hubei and Hunan were used as the research materials, the container seedling of different families was carried out in Luxian, Sichuan, an experimental base of Sichuan Academy of Forestry Sciences. The seedling growth comparison and excellent family selection were conducted based on the observation and analysis of 1-year-old seedling height and ground diameter. The variation range of seedling height and ground diameter was 14.33-55.50 cm and 3.03-6.64 mm, respectively. There were significant differences in seedling height and ground diameter between different families, which had a good basis for family selection. The variation coefficient of seedling height and ground diameter of most families was less than 15%, and the growth of seedlings was more uniform, which was beneficial to the selection and utilization of families in the future. Among the 21 families, ‘Lichuan 17’ had the best growth, the highest seedling height and ground diameter, the seedling height and ground diameter were 51.90 cm and 6.26 mm, respectively, the genetic gains were 43.08% and 22.61%, respectively. The heritability of seedling height and ground diameter of 21 families was 0.952 and 0.839, respectively. Three superior families, ‘Lichuan 17’, ‘Xuan’en 10’ and ‘Xuan’en 20’, were selected with seedling height as the main factor, and ground diameter as the auxiliary factor. The selection rate was 14.29%, and the average genetic gains of seedling height and ground diameter were 30.99% and 18.27%, respectively. The three selected families had a large selection difference, low selection rate and high genetic gain, which could provide references for the follow-up breeding.

Key words: Toona ciliata, half sib families, seedling stage, growth variation, family selection, genetic gain