Plus Trees Progeny Growth Traits Determination and Selection of Toona ciliate var. pubescens at Seedling Stage

The genetic variation of seedling traits was analyzed，and the excellent families were primarily selected based on the comparative analysis of DBH，seedling height，main root length，root biomass，stem biomass，leaf biomass，and whole plant biomass of one-year-old seedlings in 14 families of Toona ciliate var. pubescens，to provide the basis for the breeding and application. The results showed that there were very significant differences in growth traits among 14 families. The growth traits of 12 and 7 families performed well，whose ground diameter，seedling height，main root length，root biomass，stem biomass，leaf biomass，and whole plant biomass increased by 19. 84% to 28. 54%，24. 38% to 36. 32%，23. 95% to 35. 56%，23. 03% to 33. 82%，23. 86% to 35. 42%，25. 93% to 38. 52% and 23. 65% to 34. 99%，respectively，compared to the average. There was significant variation in every trait of T. ciliate var. pubescens family. The coefficient of variation of leaf biomass and seedling height reached 25. 38% and 22. 80%，respectively，indicating that the seedling height growth and leaf biomass indexes of 14 families can be used as an important evidence for early selection. Comprehensive evaluation of multi-trait indexes at seedling stage，the superior families as follows：the families 7，12，3 and 8，which seedlings grew well and the root system was developed. The research results can provide reference for the breeding and application of improved varieties of T. ciliate var. pubescens.