短轮伐期日本落叶松家系生长性状遗传参数的变化

以湖北省建始县长岭岗林场 15年生日本落叶松自由授粉家系子代测定林为研究对象 ,研究纸浆材轮伐期内不同年龄阶段生长性状的家系间遗传变异、早 -晚相关关系及主要遗传参数随时间变化的趋势 ,确定早期选择年龄及早期选择因子。结果表明 :各年龄胸径、树高不仅在家系水平上存在着极显著的变异 ,家系内个体间也存在着丰富的变异 ,具有很大的遗传改良潜力 ,家系和家系内个体选择是日本落叶松改良的主体 ;性状的方差分量、遗传力、变异系数在树木生长过程中一直处于动态变化中 ,并表现出一定的规律性 ;胸径、树高的早 -晚相关十分紧密 ,且这种相关关系主要受遗传因素制约 ;对胸径和树高进行家系早期选择的最适年龄为 6年生 ,进行家系内个体选择年龄为 8年生 ,胸径作为早期选择指标较树高更能准确地表达成熟时的信息。

Age Trends of Genetic Parameters for Growth Traits in Short Rotation Larix kaempferi Families

This study was carried out in a 15 years old progeny test of open pollinated families of Larix kaempferi in Jianshi County, Hubei Province. The genetic variation of families, age age correlations, and the age trends in genetic parameters for growth traits were analysed. Variance analysis revealed that DBH, height were significantly different from 5 to 15 years old among L. kaempferi families, and so were among individual trees within a family, which meant that there was big potential either for individual selection or family selection and they were the major sources for its genetic improvement. The variance components, heritabilities and coefficient of variances were dynamic during whole period of tree growth, and showed some common rules. The age age phenotypic and genetic correlations for DBH, height were very high, indicating that these relationships were mainly controlled by genetic factors. 6 year old was the most proper age for early selection of half sib families and 8 year old for individual selection within a family, and DBH was a better indicator than height due to its genetic stability.