Genetic Variations among Multiple Levels in Main Economic Traits of Chinese fir

Genetic variations among multiple levels in main economic traits of Chinese fir had been studied by means of two-level plantation of provenance-family at 10-year-old. The main results are as follows:(1)In the same interested trait,component of variance among individuals within familiesthat among provenancesthat among families within provenances;but heritability of provenancesthat of families within provenancesthat of individuals among families. Genetic improvement potential at different variation levels is distinct. Improvement potential of provenancethat of individual within familiesthat of families within provenances,in general. Joint selection of multiple levels will produce the biggest genetic gains.(2)In the same variation level,there are different genetic improvement potentials in different interested traits. Thus,when genetic improvement scheme of Chinese fir will be worked out,appropriate objective should be determined in accordance with different traits.(3)Selecting the good individuals within good families within good provenances,their selective advances of volume,diameter,total height,height under the first living branch are 50.55%,23.39%,17.71%,30.81%,respectively. They are much more bigger than those from the first generation genetic improvement of Chinese fir. So,at present we must pay attention to the second generation genetic improvement of Chinese fir. Both the second generation seed orchard and vegetative propagation are used for utilizing the achievements of genetic breeding and improvement of Chinese fir today.