[Effects of elevated CO2 on the Cd uptake and root morphology of different rice varieties under cadmium stress]

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 micromol x L(-1)) Cd stress increased the biomass of the two rice varieties significantly, while high levels (> 50 micromol x 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 micromol Cd x 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.