The Accumulation Ablity Of Plants At The Growth Period

Finding high accumulator was the key of phytoremediation. Whilst numerous reports suggested that metal hyperaccumulators could potentially be used to remediate metal contaminates soils, the vast majority of research on which these reports were based hydroponic laboratory studies and pot experiments that had focused on physiological and molecular aspects of metal accumulation. Only a few attempts had been made to evaluate the phytoextraction potential of hyperaccumulator plants under field conditions.The hyperaccumulators which be found in laboratory had a little biomass and grown slowly. It's hard to apply these hyperaccumulators into practice.Absorption and accumulation of Cd in the growth period by weeds and crops which grow in the Cd -contaminated soil at Zhangshi Irrigation in Shenyang were studied. In order to found out which plant could takeoff more Cd from soil, the Cd concentration and biomass of every sampled plant were treasured. In addition, Cd accumulating ability of Maize at their best harvest time of six series of maize inbred lines was investigated in a greenhouse experiment with Cd-contaminated soil sampled from Shenyang Zhangshi Wastewater Irrigation. Then absorption capacity coefficient (ACC) and transformation capacity coefficient (TCC) were used to evaluate the accumulation and transformation potential of plants. And make certain the best harvest time so as to takeoff more Cd from soil. It was given base material and substances base for phytoremediation of Cd-contaminate soil.The results were shown as follows:The accumulating ability of three crops was Zea mays> Glycine max> Oryza sativa, and the best harvest time was at the end of September, July and June respectively. The Cd concentration in Zea May was in shoot higher than that in root. It had one character of Cd hyperaccumulator.The order of accumulating ability in eight weeds was Polygonum strisnu>Solanum nigrum>Echinochloa crusgalli>Chenopodium album>Phragmites communis>Abutilon theophrasti >Acorus calaums>Lepironia articulate. The best harvest time was at the end of June, September, September, June, June, June, October and September, respectively. The distribution of Cd concentration was: shoot > root in Chenopodium album, Solanum nigrum, Abutilon theophrasti and Polygonum strisnu. They also had one character of Cd hyperaccumulator.The results showed that the period of the most strong accumulation of Cd of Mo17, 1487, Dan 598,340,5003 and 880 was 140d, 170d, 140-170d, 140d, 170d and 170d, respectively, and also was the best harvest time. If the rate of containing water in plant was calculated with 93-95%, the least absorption capacity coefficient of Cd hyperaccumulator was 84 ton per hectare expressed by fresh weight. 1487,340 and 5003 had character of Cd hyperaccumulator. The definition of Cd hyperaccumulator was extended by application of the absorption capacity coefficient. Therefore, people could select more appropriate plant for phytoremediation.