马尾松家系木材管胞形态特征的年龄变异

利用马尾松初级种子园29个半同胞家系，研究木材管胞的年龄变异。结果表明：马尾松的管胞宽度、管胞长度、管胞长宽比、管胞壁厚、壁腔比、柔性系数、刚性系数等7个指标在同年龄早晚材间均存在显著差异和极显著差异；管胞腔直径在不同年龄间差异不显著，在早晚材间差异极显著；管胞形态基本呈现出幼龄材品质优于中龄材，早材优于晚材的规律。用管胞长宽比、壁腔比和柔性系数3个指标评价马尾松的造纸制桨性能，均属优良的制浆用材；胸径年增长量与管胞形态呈显著或极显著相关，可作为造纸性能优劣的间接选择指标，尤其适用于大量遗传测定材料中的马尾松桨纸材家系的选择和改良，胸径年增长量越大，管胞的壁腔比越小，柔性系数越大，造纸性能越好；以纸浆性能和木材产量为前提确定马尾松家系的纸浆材合理采伐年龄为第15年。

Age Variation of Wood Tracheid Morphology of Pinus massoniana Families

The age variation of the Pinus massoniana wood tracheid was studied by analyzing 29 half-sib fami- lies of this tree species in primary seed orchard. The results showed that there were significant or extremely signifi- cant differences in the 7 indexes including tracheid width, length, length/width ratio, tracheid wall thickness, tra- eheid wall thickness / lumen ratio, tenderness coefficient, and rigidity coefficient of the tracheid between the early wood and the late wood at the same age. There was no significant difference in the tracheid lumen diameter among the different aged wood, but there were significant difference in the same index between the early wood and late wood. According to the tracheid morphology superior to that of the middle-aged trees, an , it was showed the law that the wood quality of the juvenile trees was d the early wood was better than the late wood. The evaluation on the pulp making properties by 3 indexes i. e. , the length/width ratio, tracheid wall thickness / lumen ratio, and ten- derness coefficient indicated that P. massoniana wood was excellent raw material for pulp making and paper manu- facture. The fact that there was significant or extremely significant correlation between annual DBH growth rate and tracheid morphology might be taken as the indirect selection index to evaluate the paper massoniana wood. It might be especially suitable for the selection and improvement of P. plenty of genetic test material for paper making making properties of P massoniana families with property performances. It was proposed that the qualified paper making properties requested greater annual DBH growth rate, smaller tracheid wall thickness / lumen ratio and greater tenderness coefficient. Taking pulp quality and wood production as the preconditions, 15-year was deter- mined as the reasonable felling age for P. massoniana families for pulp making plantations.