中文摘要：

土壤紧实是设施蔬菜生产的土壤障碍因子之一。在塑料大棚砂壤土条件下,用人工土柱栽培法研究了土壤容重分别为1.20、1.35和1.58 g·cm^-3的土壤对番茄幼苗生长和根系构型的影响。结果表明,随容重增大,叶片伸长速度、株高、植株含水量、鲜质量、干质量、根冠比、根表面积、根长密度和根体积密度等都显著降低。随容重增大,根系干质量、根表面积、根长密度和根体积密度在垂直面上的分布显著降低,容重1.58 g·cm^-3处理的根系全部分布在0~6 cm土层内。高容重土壤使根毛区皮层产生形变,即细胞变长,皮层下陷,根表面凹凸不平,根圆度变差,偏心率增大,降低根毛区的吸收能力。

英文摘要：

Soil compaction is one of soil restricting factors for greenhouse vegetable production. The effects of bulk density of 1.20（D1.20）,1.35（D1.35）and 1.58 g · cm^-3（D1.58）in sandy loam on seedling growth and root architecture of tomato were investigated using soil columns in greenhouse. The results showed that leaf elongation rate,plant height,plant water content,fresh and dry weight,root to shoot ratios were negatively correlated with soil bulk density. Root surface area,root length density and root volume density also decreased significantly with increasing soil bulk density. High bulk density inhibited root penetration to deep soil,and consequently influenced root distribution,e.g. roots were confined to the top 6 cm soils in D1.58 treatment. In soil profile,the distribution of root mass,root surface area,root length density and root volume density decreased significantly with increasing soil bulk density. In root hair zone,root invagination and cell deformation occurred in outer cortex under D1.58,and the roundness（R）and eccentricity（e）of root transverse section increased significantly with increasing bulk density,which indicated that the ability of root uptake would decrease. It is concluded that a decrease in soil cultivation layer would inhibit root growth of the deep-root vegetables such as tomato plant.