火炬松种源顺纹抗压强度的变异与木材密度的关系

VARIATION OF CRUSHING STRENGTH PARALLEL TO THE GRAIN OF 31 PROVENANCES FOR LOBLOLLY PINE AND ITS CORRELATION WITH WOOD DENSITY

同一环境１０年生火炬松种源试验林材性分析结果表明：①３ｌ个火炬松种源间顺纹抗压强度近似于正态分布，其均值幅度为２３．７～２９．７ＭＰａ，对照种源为２６．６ＭＰａ，处于中等水平。方差分析表明种源间顺纹抗压强度差异显著，但多重比较显示仅部分种源间有显著差异；顺纹抗压强度广义遗传力为０．６１８，种源内顺纹抗压强度差异大于种源间，说明在种源选择的基础上再进行个体选择，效果会更好。②基本密度、气干密度和绝干密度间相关极为显著，三者与高度相关，非破坏性取样测定基本密度可很好预估顺纹抗压强度值。③顺纹抗压强度值与胸径、材积负相关，顺纹抗压强度值与晚材率正相关，材性育种可选择生长快、晚材率高的种源、个体来解决“生长快强度稍低”矛盾。④原产地纬度与顺纹抗压强度正相关显著，高纬度种源引种到低纬度区域种植，其顺纹抗压强度值有增大的趋势。

Wood properties of 306 l0 years old trees of 3l loblolly pine(Pinus taeda L.) provenances were reported in this paper.The distributive pattern of crushing strength parallel to the grain was similar to normal distribution. The range of mean was from 23.7 MPa to 29.7 MPa. The of contrast provenance was 26.6 MPa and in the middle of 3l provenances. Variance anylysis showed that the disticnt difference existed among these provenanes, but Duncan's multiple range test(P=0. 05) indicated that the difference existed only among parts of 3l provenances. The broad sense heritability of was 0. 618. The variation coefficients of within each provenance was greater than that among provenances。That means that selection within a provenance might be efficient.Specific gravity was singnificantly related with wood density at l2%moisture content and oven-dry density of wood ,and these three types of wood density were also singnicantly related with .This meaned that specific gravity determined by non-denstructive sampling could be used to precisely predicated .The was positively distinct related with latewood percoent and negatively with D.B.H.,volumes of trees, To solve the contracdition of fast growth trees with relatively low mechanic properties, the provenances with high percentage of latewood and fast growth property would be selected and planted.The provenances' altitude of local regions was postitively related with .The provenances introduced from higher altitude regions were planted in lower altitude regions and its would increase.This geographic variant trend could be used to guide afforestion to get building timber with high mechanic properties.