不同砧木类型板栗根系分布特征

为探明不同砧木类型板栗(Castanea mollissima)根系分布特征,以河北省迁西县北京林业大学经济林(板栗)育种与栽培实践基地3种砧木类型(单芽砧、双芽砧、1年砧)的5年生板栗为研究对象,采用壕沟法研究根长、根表面积、根体积和不同径级根系等指标的水平及垂直分布特征。结果表明:(1)水平方向上,单芽砧板栗根系主要集中在距树干20~60 cm处,双芽砧板栗根系主要集中在距树干40~100 cm处,1年砧板栗根系在距树干20~100 cm呈均匀分布。垂直方向上,板栗根系主要集中在20~40 cm土层处。(2)双芽砧板栗根系根长、根表面积和根体积均显著高于其他2个处理。(3)3种砧木类型根系的不同径级中,0~1 mm径级根系根长和根表面积最大,根体积最小。与1年砧(对照)相比,单芽砧和双芽砧板栗0~1 mm径级根系根长和根表面积变化较大。

Distribution Characteristics of Castanea mollissima Root of Different Rootstock Types

The experiment was conducted to study the root distribution characteristics of different rootstock types.In October 2016, different rootstock types of five-year-old chestnut in economic forest ( Castanea mollissima) breeding and cultivation practice base of Beijing Forestry University in Qianxi, Hebei Province were used as experiment materials.Excavating meth-od was used to study the horizontal and vertical distributions of root length, root surface area, root volume and root charac-teristics of diameters.The roots of single-rootstock grafted bud seedlings were concentrated in the 20-60 cm from the trunk in the horizontal direction, double-rootstock grafted bud seedlings were concentrated in the 40-100 cm and one-year-old ro-otstock were homogeneous in the 20-100 cm.The roots were concentrated in 20-40 cm deeper of soil layer in the vertical direction.The root length, root surface area and root volume of double-rootstock grafted bud seedlings had a significant higher than others.Under the three rootstock types, the root length and root surface area of 0-1 mm were the highest in dif-ferent diameters, while the root volume was the lowest.Compared with the one-year-old rootstock, the 0-1 mm diameter roots of single-rootstock grafted bud seedlings and double-rootstock grafted bud seedlings had bigger change on root length and root surface area.