中文摘要：

为了探讨CO2浓度升高下不同水稻品种荣优398（RY）和粤杂889（YZ）吸收重金属Cd差异性的原因,利用水培试验研究了不同浓度Cd处理下两种水稻吸收Cd的差异及根形态的变化特征.结果表明：低Cd处理（5、10、20μmol·L-1）显著增加水稻生物量;当Cd浓度高于50μmol·L-1时,Cd胁迫效果开始显现,水稻生物量减少.CO2浓度升高显著增加了水稻的生物量,增加了YZ茎Cd含量而降低了RY茎Cd含量.在5～200μmol·L-1的Cd浓度下,CO2浓度升高增加了YZ活性根在总根长中的比例,降低了RY活性根的比例.CO2浓度升高下不同水稻品种根形态的变化是导致其对Cd吸收差异性的原因之一.

英文摘要：

A hydroponic experiment was conducted to study the effects of elevated CO2 on the Cd uptake and root morphology of rice varieties Rongyou-398（RY） and Yueza-889（YZ） under different levels of Cd stress.Low levels（5,10,and 20 μmol·L-1） Cd stress increased the biomass of the two rice varieties significantly,while high levels（50 μmol·L-1） Cd stress was in adverse.Elevated CO2 increased the varieties dry biomass significantly,and increased the stem Cd concentration of YZ but decreased that of RY.Under the stress of 5-200 μmol Cd·L-1,elevated CO2 increased the proportion of active root length in total root length of YZ but decreased that of RY,which could be one of the main reasons for the difference in the Cd uptake of the two varieties under Cd stress.