The Impact Of Road Traffic On Physiological Characteristics And Heavy Metals Of Rice

To explore the impact of road traffic on physiological characteristics and heavy metals content of crop beside road, using pot experiment and indoor physical and chemical analysis method,research the impact of road traffice on physiological characteristics, heavy metals, yield and its constitutes of rice at different distances during the jointing and heading stage. The main results are as follows:1.Stomatal conductance, intercellular CO2 concentration,net photosynthetic rate, transpiration rate and total chlorophyll content of the rice leaves in heading stage were more than in jointing stage. Stomatal conductance at 50m was the minimum in the two periods,and it was significantly different with 150m. In the jointing stage, Ci,Pn, Tr of leaves were all the highest at 10m. In heading stage,Ci wasl0m>150m>50m, the difference were not significant. Net photosynthetic rate, transpiration rate were the highest at 150m,and the difference were significant. Water use efficiency of the leaves at 50m was the highest in the jointing stage, which was significant difference with 150m. Water use efficiency was not significant in heading stage. Chlorophyll a, chlorophyll b, total chlorophyll content at 150m in the two periods were relatively higher, there was no significant difference in the jointing stage, but in heading stage was significant. Chlorophyll a/b at 150m were relatively lower,with no significant difference in jointing stage were, significantly difference in heading stage.2.The free proline content,cell membrane permeability, MDA content, soluble sugar, soluble protein content and activity of protective enzymes of rice leaves at three distance pots were all not significant differences in jointing stage. In heading stage, free proline content was decreased with the distance to the subgrade increases, the difference was significant. Heading stage, leaf cell membrane permeability, MDA content were highest at 50m.10m,50m were significant differences compared with 150m.Heading stage, the soluble sugar content was 150m>10m>50m, were significantly different. Soluble protein content were higher in heading stage than jointing stage,10m>50m>150m, but the difference was not significant, soluble protein content were not significantly affected. In heading stage, SOD activity at 10m was 13.37% higher than 150m,50m was 21.28% higher than 150m,the differences were both significant. CAT activity in rice leaves in the two periods were 50 m>10m>150m, the differences were not significant. In heading stage, POD activity at 10m was 19.65% higher than 150m,50m was 25.87% higher than 150m, the differences were significant.Protective enzymes activity was higher in heading stage than jointing stage,indicating that with the growth time of rice growth increasing,the impact of road traffic pollution increased,protective enzymes activity help to protect plants from harm.3. Pb, Cu, Zn, Cd content in soil of 10m,50m more than 150m, at harvest only 50m Pb content slightly lower than 150m, Pb content decreased, there were no significantly change in Cu, Zn content, in a growth cycle of rice, within 150m from the road, there were not increased significantly, both comform the national soil environmental quality standard. However, the content of Cd element appears increased significantly at 10m in harvest. Pb,Cu,Zn,Cd content in plants were more than brown rice. Pb, Cu, Zn contents of brown rice in the 150m range of were not exceeded, in line with health standards of Rice. Cd element content has exceeded in the 50m range,10m was more than 50m. The Cd content of brown rice at 150m is safe. Pb content in 10m, 50m of the hull were higher than in brown rice, Pb, Zn contents of the rice hull are relatively low levels at 150m, with significant difference, Cu content changed little, Cd content in the 50m was 30.16% higher than the 150m,the the difference was significant, 10m was 5.37% lower than the 150m, the difference was not significant. Cu,Cd content of plants at 10m had the highest value. Pb, Zn contents were highest at 50m.4.Plant height, main spike, spike length, flag leaf length and width are relatively large at 150 m, relatively minimum at 50m. Effective panicles per plant, filled grains per panicle, seed setting rate of the 150m is relatively high, but the difference was not significant.Grain weight was the lowest at 50m,which was 7% lower than 150m, the difference is significant,10m was 2% lower than 150m, the difference was not significant. Pot yield was the highest at 150m, which had a relative significant difference to 10m,50m.