在两种种植密度下对8个测交种的根系形态及在0～60 cm土壤剖面的分布进行测定。结果表明，根长、根干重和根拔拉力均具有显著的基因型差异，其中，L105和L109属于大根系基因型；L172和L224属于小根系基因型。L132、L160、L224对密度的反应较为敏感，L219对密度的反应较为迟钝。在增加种植密度后，各基因型根系均有纵向延伸的特征，不同基因型根长和根干重在不同土壤层次间分布比例差异较大，且其对密度的反应仅表现在特定的土层内。

An experiment was conducted to evaluate the root morphology of eight genotypes and their distribution in 0-60 cm soil layer in different planting density treatments. The results indicated that there were significant differences for root length, root dry weight, and vertical root pulling resistance. L105 and L109 had the larger root system, L172 and L224 had the smaller root system. L132, L160 and L224 were more sensitive toplanting density except for L219. The root presented the vertical extension with the increasing of density. There were significant genotypic differences in different soil layers for root length and root dry weight. The reaction of genotypes on root system was in specific soil layers in different planting density treatments.

国家自然科学基金（31101611）、中国博士后科学基金（2012M51081）、吉林省青年科研基金（201201090）、科技支撑课题（2013BAD07B02，2011BAD16B10，2012BAD04B02）、吉林省科技支撑重大项目（20106025，20126026）