火炬松半同胞家系遗传测定与早期性状评定

对15年生火炬松半同胞家系的生长和材性性状测定表明:火炬松家系树高、胸径、材积、木材基本密度、纤维素含量、管胞长度与宽度等具有显著的差异;在家系水平上,木材基本密度、纤维素含量、管胞长度与宽度和材积生长相关不明显．遗传力测定表明:家系生长性状与材性性状平均遗传力均较高,达到中等程度以上．对树高生长、胸径生长、木材基本密度、纤维素含量、管胞长度与宽度等性状进行年度相关、早晚期选择研究表明:火炬松家系的生长相关主要由遗传决定;树高从第5年开始,胸径从第4年开始与以后各年的相关系效均在0．7以上,表明以此为最低年龄进行早期选择有较大的可靠性;木材基本密度10年生与其后各年龄级的相关系数值趋于稳定,术材密度最低选择年龄为10年;木材纤维素含量11年生与其后各年龄级的相关系效值趋于稳定,木材纤维素含量的最低选择年龄为11年．

Genetic Test and Character Evaluation of the Half-sib Families of Pinus taeda L.

The growth and timber characters of 15-year old half-sib families of Pinus taeda L. were investigated. The results indicate that there were significant differences among different Pinus taeda L. families, which included the height, diameter at breast height (DBH), volumei wood basic density, cellulose content, tracheid length and width. On the family level, there were no significant correlations between wood basic density, cellulose content, tracheid length, tracheid width and volume increment. The genetic test shows that the mean heritage of growth and timber characters of Pinus taeda L. families performed great and reached more than moderate extent. The annual correlation and early, late selection of height, DBH, wood basic density, cellulose content, tracheid length and width show that the growth correlation of Pinus taeda L. families was mainly determined by their genetic performance : height since the 5th year on, DBH since the 4th year on, their correlative coefficient between annual growths reaching more than 0. 7. Therefore, at the youngest age, there is great reliability to play early selection. Since the 10th year on, the correlative coefficient of wood basic density tends to keep stable and the cellulose content since 11th year on also shows similar trend as wood basic density, so the youngest selection age of wood density and cellulose content is the 10th and llth year, respectively.