13种沙生植物纤维和导管分子长度变异的研究及木质部特征的定量研究

对13种沙生植物的纤维长和导管分子长度进行了测定分析， 二者的径向变异规律呈现上升，下降, 波动或恒定不变趋势。所选树种的平均纤维长度小于900 μm，属于较短纤维。所选树种的纤维长度和导管分子长度除沙冬青年轮内差异不显著外，其他树种间及树种年轮间的差异极其显著。对沙生植物的解剖特征的定量研究可以看出，所选树种的次生木质部特征体现了对沙漠环境的高度适应性。较短，孔径较窄导管以单管孔或复管孔形态出现，纹孔较小使干旱区沙生植物具有较大的水分运输能力，也是水分安全传导的一种策略。

QuantitatiVe Characteristics of Xylem Cells and Variation in Vessel Element Length and Fibre Length for 13 Psammophytes

Fibre length and vessel element length were measured and analyzed in 13 psammophytes grown in arid sandy region, and the horizontal variations of them showed decreasing, increasing, considerable fluctuations or constant tendency with age. Fibre length is less than 900 μm which included in short range according to IAWA Committee. There was significant difference in both fibre length and vessel element length among-tree and within-tree except A. mongolicus. From the quantitative study of anatomical characteristics, the secondary xylem cells have high adaptability to desert. Vessels solitary or grouped in multiples with small diameter, very short elements and minute pits are in respond to demands for greater water transport capacity and the above appearances in the xylem of arid zone species are interpreted as a strategy for conductive safety.