10年生火炬松木材28个家系干缩率的变异分析

对10年生火炬松28个家系的6项干缩率指标的统计结果表明：16、24、27、32家系的干缩率较小，可作为建筑材的首选优村家系；家系间整体变异系数较小，家系内个体变异大多很大，在家系基础上进行个体改良效果更好；28个家系的全干干缩率与气干缩率密切相关，在全干和气干状态时，弦、径向干缩率比值T/R亦显著相关。

Analysis on Variation of Drying Shrinkage of 10 Years Old Loblolly Pine Wood from 28 Families

In the 6 drying shrinkage indexes of 28 families of 10 year old Loblolly Pine wood of the radial shrinkage and volume shrinkage in oven and air dry conditions were all notable different at 0.01 remarkable level while the tangential shrinkage in oven and air dry conditions were notable different at 0.05 remarkable level. The results showed that the shrinkage of 16, 24, 27 and 32 family were lower among the 28 families. The variations of individual in a family were mostly higher than those among the families. These suggested that the effect of genetic improvement of forest tree could be better for individuals in a family. In addition, the oven and air drying shrinkage of wood from 28 families were closely correlated, e.g. tangential correlative coefficient was 0.8927, radial correlative coefficient was 0.8931, volume shrinkage was 0.8099, all of those reached a remarkable correlation at 0.01 level. The ratio between tangential and radial shrinkage ( T/R ), the correlative coefficient in oven and air dry conditions was 0.8901 which also reached a remarkable correlation at 0.01 level.