The Difference In Capacity Of As Accumulation Among Populations Of Pteris Vittata L. And Related Physiological Characteristics

Recently, phytoremediation of Arsenic contaminated soil based on Pteris." vittata has been paid more and more attention. Therefore improving the efficiency of remediation and comprehending the mechanisms of arsenic hyperaccumulation are of great importance in this field. 10 populations of P. vittata came from 10 regions in 7 provinces in China, including Anhui, Chongqing, Hunan, Taiwan, Fujian, Guangxi and Guangdong were studied in this research. The difference in As-accumulation and morphologic traits were identified, and several key process related to As-accumulation were found by comparing the different population in the ability of transpiration and absorption of As by the roots. The main results were summarized as follows:1. There were significant difference in morphologic traits, such as the biomass, the height, the number of the fronds per shoot, the density of pinnae, the shape of pinnae, the leaves acreage and so on. Based on these morphologic traits, the10 populations could be divided into three groups. The biomass, the height and the number of the fronds were highest in group which was in the southwest of the research area and lowest in the group which was in the southeast of the research region.2. The capacity of As-accumulation in the pinnae was significantly different among this populations. Based on the arsenic concentration of pinnae, the 10 populations could be divided into three groups by the method of Classify Analysis (Hierarchical Cluster). The As-accumulation of aerial part was not significant difference between high As-accumulation group and medium As-accumulation group. But the arsenic concentration of pinnae, Ratio in As concentration of pinna to root and As-accumulation of aerial part in Low As-accumulation group were singnificantly lower than the other two group.3. There was significant difference in the capacity of transpiration among this populations. The transpiration in the High As-accumulation group was much higher than in the Low As-accumulation group. And the phosphorus absorption has not significant relation to the capacity of As-accumulation in P. vittata .4. The characteristic of root arsenic absorption was different among populations. As the uptake kinetic parameters, Imax, Km and Cmin showed their differences among the populations. The High As-accumulation group had the smaller Km and Cmin but larger Imax , suggestingthat a high-affinity transport system for arsenate uptake in the root cell plasma membrane played important role in As-accumulation.It was the first time that the As-accumulation capacity was found to be significantly different among the populations of P. vittata. The difference in transpiration by pinnae, arsenic absorption by root among the populations seemed to have direct influence on the capacity of As-accumulation. The information is important for improving the remediation efficiency and help to resolve the mechanism of As-hyperaccumulation.Finally, the geographical distribution maps of P. vittata in China were acquired, and the ecological adaptability of P. vittata were summarized. It is be useful to determine the geographical area that Chinese Brake fern could be used to remediate the As-contaminated soils.