皮层和中柱对水曲柳和落叶松吸收根直径变异的影响  

Effects of Cortical Thickness and Stele Diameter on Variations of Root Diameter in Fraxinus mandshurica and Larix gmelinii

作　　者：谷加存[1] 赵妍丽 王文娜[1] 王韶仲[1] 王政权[1] 

机构地区：[1]东北林业大学林学院,哈尔滨150040

出　　处：《林业科学》2014年第10期59-66,共8页Scientia Silvae Sinicae

基　　金：中央高校基本科研业务费专项资金项目(DL12CA06);国家自然科学基金项目(31100470);国家林业科技支撑计划课题(2011BAD37B02-2)

摘　　要：采用植物解剖学和通径分析方法研究皮层和中柱对水曲柳和落叶松人工林根系前2级根（最末端的根尖为1级根）直径变异的影响。结果表明：1）根直径、皮层厚度和中柱直径具有明显的季节变化,三者具有相同的变化规律;2）随着皮层厚度或中柱直径的增加,根直径显著增加,皮层厚度可以解释直径变异的85%-95%,中柱直径可以解释直径差异的92%-97%,表明皮层和中柱均对直径变异有重要的影响;3）通径分析结果显示,水曲柳根直径变异和季节变化主要是皮层变化起直接作用,中柱仅起间接作用;而落叶松则是皮层起间接作用,中柱起直接作用。研究结果为认识木本植物吸收根种内直径变异的机制提供重要基础。The diameter of fine roots plays an important role in root physiological and ecological functions of woody plants. Fine root diameter varies greatly within or among tree species,even at the same root branch level. However,the underlying mechanism for such variation remains unclear. Although fine root morphology and anatomy in woody plants have been extensively studied during past decades,it is poorly understood for the mechanism of diameter variation in absorptive roots. In this study,we sampled fine roots from Fraxinus mandshurica and Larix gmelinii plantations,and measured root morphological（ diameter） and anatomical traits（ cortical thickness and stele diameter）,and used path analysis to examine the effects of anatomical traits on root diameter variation of the two species. There were substantial and similar seasonal variations in root diameter,cortical thickness and stele diameter in both species. Root diameter increased with increasing of cortical thickness and stele diameter. Correlation analysis indicated that 85%- 95% of the variations of root diameter could be explained by the variation of cortex thickness,and 92%- 97% by variation of stele diameter,suggesting that the anatomical traits were important for root diameter variation in the two species. Path analysis showed that root diameter variation in F. mandshurica was affected directly by cortical thickness,and indirectly by stele diameter,however in L.gmelinii,it was affected directly by stele diameter,and indirectly by cortical thickness. These results may help us understand the mechanism of diameter variation of absorptive roots in woody plants.

关 键 词：根序 根直径 人工林 通径分析 细根 

分 类 号：S718.41[农业科学—林学]