杉木全同胞家系的遗传分析及重要树冠因子的筛选

通过对5年生杉木6×6全双列杂交(Griffing Ⅲ)试验林的调查与分析，研究杉木若干性状的遗传与变异规律，并筛选决定理想株型的重要树冠结构因子，为杂交育种和杉木理想株型无性系选育提供科学依据。运用转化分析法来处理不平衡试验数据，结合配合力分析法、相关分析法和通径分析法,研究杉木遗传变异、基因作用方式和重要树冠因子的选择。通过对杉木若干性状进行研究，获得了不同性状遗传变异大小。结果表明，杉木材积、枝下高和饱满度等性状具有中度遗传变性，树高、胸径具有窄的遗传变异性，同时杉木改良性状具有中度以上的遗传力，因此杉木生长形质性状宜采用连续多世代改良；在杉木生长、形质性状和树冠结构性状中，12个研究性状有8个重要性状的基因作用方式以非加性遗传基因效应为主，杉木高世代育种亲本是多世代与高强度选择的产物,杂合体居多,杉木的多性状、高世代遗传改良以杂交育种为主；生长、形质和树冠结构性状间具有明显的遗传相关性，通径分析揭示:决定杉木理想株型育种中重要树冠结构性状是冠形率和树冠表面积大小。由此可见:杉木多性状、多世代连续改良以杂交育种为主，杉木无性系理想株型选择时，应注重冠形率和树冠表面积的作用。

Genetic Analysis of the Full-sib Families and Screening on Important Canopy Factors in Chinese fir

Through the analysis of 6×6 diallel cross test (Griffing Ⅲ) planatation of Chinese fir,genetic variation and hereditary variability of the growth,shape-quality and canopy factors of Chinese fir were studied,key canopy factors determining ideotype were screened to provide basis for cross breeding and the selection of ideotype.Based on the transformation theory by Qi Ming (2009),several characters of Chinese fir were studied.The results showed that there existed moderate genetic variability in timber volume,height under branches and fullness.The tree height and DBH had narrow genetic variability,and the economic characters had moderate heritability.Growth and shape-quality should be improved by successive generations.The results of combining ability showed that among the 12 traits of Chinese fir studied,the gene action mode of 8 important traits,such as growth and canopy structures were controlled by non-additive gene effect.Analysis of several economic characters,non-additive genetic effect had significantly exceeded the additive genetic effect.Chinese fir high-generation breeding parents were the product of multi-generation and high-intensity selection，heterozygotes predominate.Hybrid breeding should be the main method for the multi-character and high-generation genetic improvement of Chinese fir; There were significant genetic correlations among growth,shape-quality and crown structural traits.Path analysis revealed that crown shape rate and crown surface area were the important crown structural traits in the breeding of ideotype of Chinese fir.Selecting clones with ideotype,the crown shape rate and crown surface area must be paid more attention.