Comparative Study on Genetic Gains of Chinese Fir Improved Varieties

The genetic-gain-test plantation located in Kaihua County of Zhejiang Province collected 34 Chinese fir improved varieties which were from 6 superior provenances, 18 good families, 2 better clones selected preliminarily in Zhejiang, 4 seedlots from first generation and 1.5-generation corresponding local clonal seed orchards (CSO), 3 superior provenances from the provenance seed orchard (PSO) in Kaihua County and a CK.The results for these plantations at age 5 showed that it is possible to acquire great genetic gains through provenance, family and clone selection.It was found that the real gains of the preliminarily selected clones and good families were the greatest (55.2%) among the improved varieties tested for volume at age 5.The average tree growth of the best family was 5.88 m in height, 10.1cm in DBH and 106.9% in volume over those of the CK.The real volume gains of 1.5-generation CSO, first generation CSO and superior provenances were 37.7%, 28.2% and 27.6% respectively.For the superior provenances from PSO, its stem volumes were 31.4% over CK (between first generation and 1.5-generation CSO).Among the improved varieties, the preliminarily selected clones and good families possessed the smallest phenotype variation coefficients and similar individual performance.This paper also puts forward some suggestions for the research, production and application of Chinese fir improved varities in Zhejiang.