火炬松木材纤丝角和管胞长度的变异及其相关分析

在３处立地上各选５株１７．５ａ生火炬松木材，分别测定其管胞长度、纤丝角，并对２性状间的相关性进行了分析。结果：火炬松管胞长度由髓心向外递增，纤丝角由髓心向外递减，２性状在径向上呈显著的线性负相关；３处立地上林分内以及不同立地上林分间２性状均不呈显著的负相关，这说明株间木材管胞长度不能预测纤丝角。林木育种在评定优良种源、无性系，以及营林培育评价营林措施对木材材质的影响时，只能实测纤丝角。

VARIATION OF TRACHEID LENGTH AND MICROFIBRIL ANGEL OF LOBLOLLY PINE GROWN IN DIFFERENT SITES AND THEIR RELATIONSHIP

trees of 17.5-year-old loblolly pine grown in three different sites were collected. Variations of tracheid length(TL) and microfibril angle(MFA) in secondary layers of tracheid wall, as well as the relationship between TL and MFA were studied. In radial direction TL increased from pith outward and MFA decreased, TL was significantly linear negatively related to MFA within trees. But this relationship was not found between trees within each same stand of three different sites, neither between trees among stands of three different sites. This means that TL is not able to predict MFA,i.e.,selecting TL in wood improvement is diffcult to control variation of MFA. Therefore if better provenances or better clones in tree improvement are selected to expertize and effects of forest practices on wood properties are envalued, it is the only way to determine the MFA of sampling wood.