长柄水青冈幼苗根系构型及动态变化

长柄水青冈（Fagus longipetiolata）是我国亚热带山地林的重要组成树种,本研究在温室中用河砂培养长柄水青冈幼苗,采用直接测量法研究了长柄水青冈的根系构型。结果表明,生长50 d的长柄水青冈幼苗的根系呈倒圆锥形,根宽小于根深;基根平均生长角度较小,基根的向地性小;一级侧根与主根的夹角从根系上部至下部逐渐变小;二级侧根首先发生于根系的中下部,然后其发生范围向根系上、下部扩展。虽然长柄水青冈幼苗根系构型存在较大的个体差异性,但一级侧根与主根的夹角则具有较好的稳定性。研究揭示了实验条件下长柄水青冈幼苗的根系构型及其在幼苗建成过程中的生长变化规律,为长柄水青冈的进一步研究提供科学依据。

Root Architecture and Dynamic Changes of Seedling of Fagus longipetiolata

We studied the root system of Fagus longipetiolata seedlings to：（1） show the root architecture of Fagus longipetiolata;and（2） determine variation regularity of root architecture during the process of growth.Fagus longipetiolata seedlings were grown in plastic vessels in a greenhouse,and watered with nutrient solution.Results indicated that the root system was reverse circular cone in shape and the width was less than the depth.The basal roots were distributed near the surface of the growth medium,and the angle of first-order lateral root and main root decreased gradually from root base to root tip along the main root.The second-order lateral root developed firstly between the middle and lower part of the root system.There was great variability in root architecture parameters of Fagus longipetiolata,while angle of first-order lateral root and main root showed the least variability among architectural parameters.