杉木不同水平试验林的遗传参数估算和高世代育种的亲本评选

Estimation on Genetic Parameters for Chinese Fir Test Plantations of Different Levels and Selection of Parents for High Generation Breeding

利用杉木种源试验、杉木半同胞子代自由授粉试验和杉木全同胞子代试验3类共6片试验林中材积、树高、胸径、枝下高、枝高比和木芯密度共6个性状的资料,采用转化分析原理,进行方差分析以获得各种参数,在此基础上采用主成分指数和基本指数公式,按较大的入选率进行逆向选择,以获得若干优良种源和优良家系(半同胞或全同胞),然后采用优良家系(种源)和优良家系(种源)内优良个体联合选择的策略,通过控制入选率来避免高世代育种群体中的近交的方法,展开高世代亲本评选。基于杉木各经济性状间的遗传相关结果,选取材积和木芯密度(或枝高比),作为杉木多性状改良的选择性状,按材积个体育种值经济权重0.60和木芯密度个体育种值(或枝高比)经济权重0.40的比率,构建单株个体的选择指数。最终从6片试验林,共10 732子代中选择115株优良个体,成为杉木高世代育种群体中的待测亲本。

Three categories of Chinese fir progeny test,provenance trial,open pollination progeny test and full-sib progeny test,were conducted to acquire superior provenances and families.Genetic parameters were obtained by analysis of variance according to the data of volume,tree height,diameter at breast height（DBH）,bole height under the first living branch（BHLB）,ratio of BHLB to total height（RBTH） and wood density of trees in six experimental plantations.Based on this,adverse selection on treatments was implemented using selection index and basic index formula in terms of high selection rate.Then,the joint selection strategy among families and individuals within family was used to select the populations for the advanced generation breeding by controlling the selection rate to avoid inbreeding depression.Volume and wood specific gravity（or RBTH） were selected as the target traits for advanced generation and multi-trait improvement of Chinese fir based on the genetic correlation among different economic traits.The selection index for individual tree was constructed by the economic weight of volume breeding value 0.60 and breeding value of wood specific gravity（or RBTH） 0.40.A total of 115 superior individuals were selected out from 10732 offspring in the six experimental plantations,which became the parents to be tested in advanced generation breeding populations of Chinese fir.