论文部分内容阅读
Many previous studies dealing with the genotypic variation of Cd uptake have been carried out in a hydroponic culture with a single Cd level and plant seedlings are frequently used.Apparently,the soil environment is more complicated than solution condition and the results of seedling stage may not accord with maturing stage.Hereby,we have used a pot experiment with a series of soil Cd levels to study the genotypic variation of Cd uptake and distribution by maize in maturing stage,and mineral nutrient Cu,Zn by three maize genotypes in mature stage were also determined.Increase of soil Cd level from 0 mg kg-1 to 21 mg kg-1 inhibited in different degree the biomasses and yield of three genotypes.Chunyou30 had the higher tolerance to the Cd contamination,while Jitian6 was most sensitive to Cd.The root biomasses were decreased significantly for Jitian6 and stimulated for Jidan209 and Chunyou30.Yields of three genotypes maize was decreased by increasing soil Cd concentrations.Among of them,Chunyou 30 had a high tolerance and Jitian6 was most sensitive to Cd.The accumulation order of Cd in different parts of plants was root>leaf>stem>grain.The percentage of absorbed Cd by roots was 70%-85%of total absorbed amount.Cd uptake by maize in mature stage had a significant genetic variation: Jitian6>Jidan209>Chunyou30 for root,stem and leaf,and Jidan209>Jitian6>Chunyou30 for grain,respectively.Increase of soil Cd had no significant effect on Zn concentration of leaves,but there was a significant genetic variation: Chunyou30>Jidan209>Jitian6(P=0.023).Jitian6 had the highest Cd concentration and lowest Zn concentration; therefore,this maize genotype would increase the heath risk to animals and human if cultivated in Cd contaminated soil.Cu concentration of leaves was increased significantly with increase of soil Cd(P<0.01)but no genetic variation was observed.