中文摘要：

制作开顶式气室控制CO2浓度，对盆栽大豆进行试验测定，分析了大豆根系生长和生理特征在CO2浓度升高条下的变化。结果表明，随着CO2浓度的升高，大豆根系生长受到明显促进，根系更加发达，表现为根系体积、生物量以根冠比的显著提高，主根长度、直径和侧根密度亦呈增加趋势。CO2浓度为450、550、650和750μmol/mol时，与CO2本浓度相比，大豆苗期根系体积增加10．2％～36．7％，开花期提高13．2％～34．7％，鼓粒期增幅达13．9％～49．4％。根干重的提高幅度与根体积增幅基本一致，根冠比随CO2浓度升高而加大。同时，高浓度CO2条件还促进了根系活跃吸面积的增加和根系活力的加强，根系活跃吸收面积的增大在开花期较为显著，增幅为6．9％-29．9％，根系活力在开期和鼓粒期增幅较大，分别提高6．8％-25．0％和7．2％-24．4％。件及底系收花

英文摘要：

The root characteristics including root volume, root dry weight, length of main root, ratio of root dry weight to shoot dry weight, root active absorbing area and the activity of root in soybean were measured under ambient and elevated CO2 concentrations, and their responses to elevated CO2 were analysed. The results showed that growth of root system was promoted significantly under high CO2 levels. The root volume increased by 10.2% -49.4% under elevated （450,550, 650 and 750 μmoL/mol） CO2, compared to the ambient air CO2 concentration. The ratio （Root/Shoot） increased with CO2 enrichment. On the other hand, the root active absorbing area increased by 6.9% -29.9% at flowering stage. The activity of root increased by 6.8% - 25.0% and 7.2% -24.4% at flowering and pod-setting stage under four high CO2 levels.