Influences of Growth Improvement of Chinese-fir at Different Generations upon Wood Density
s:Growth traits are the main selection criteria for the first two generations of the Chinese fir breeding programs.However breeders need to be aware of possible negative influences of such selection crite-ria on wood density.This study examined the genetic variation and inheritance of wood density ,and its relation-ship with growth traits by using the first generation and the second generation progeny testing plantations ,and indirect influences of growth improvement on wood density was studied when growth traits were directly select -ed from each generation .The results were as follows as:( 1) with the advancement of generations ,amplitude of genetic variability of volume ,H,DBH and wood density didn't shrink;( 2) in addition,there was negative ge-netic relationship between wood density and growth traits ,especially with the advancement of generations ,this negative genetic relationship still rose;(3) although wood density had smaller genetic variability than growth traits,but was favorable on one hand ,wood density had higher individual heritability .This means that there were considerable genetic gains by mass selection .Thus it can be seen that timber properties improvement must be incorporated in multi -generation improvement programs ,and the improvement of wood properties will lay on a suitable position in advanced generations breeding of Chinese fir .In order to achieve good genetic effects ,it is suggested that hybridization breeding be used for producing materials with fast growth and good wood qualities , and the integrated selection index method may be used for selection on excellent materials ,breeding achieve-ment may be used by means of asexual propagation or hybridization seed orchard .
Chinese-firfirst generationsecond generationopen pollinationprogeny testwood density
国家科技期刊平台
NSTL
万方数据
维普
