| Brassica napus1."Sue you1" was selected as research object. Through adding different concentration cadmium ratio, remediation capability of rape on cadmium pollution was discussed using soil pachycondyla method. Hope to be able to provide more theoretical and technical support in repairing the heavy metal pollution in soil.1. Selection of experimental materials. The resistance of mustard type rape to cadmium is superior to brassica napus1. However, brassica napus1."Sue you1" was selected ultimately considering its bid biomass, strong local features and cadmium pollution concentration in our country.2. Experiments showed that cadmium can strongly inhibit germination ratio of rapeseed, and this trend increased with the concentration cadmium ratio. Germination rate was only16%when concentration cadmium ratio was50mg·kg-1. Resistance reaction of rape was also caused along with accumulation of cadmium in rapeseed body which mainly displayed in the content variation of MDA, H2O2, soluble protein, GSH and GSSG. MDA content increased significantly following cadmium concentration increasing and the trend in the rich loam was particularly obvious, this explained that organic matter could improve the stress of oxidation conditions; in rich loam, H2O2content displayed an upward trend with cadmium concentration increasing, in lean loam, H2O2content increased significantly between5mg·kg-1and20mg·kg-1of concentration cadmium ratio, decreased when concentration cadmium ratio increasing to50mg·kg-1; in rich loam, soluble protein content rose when concentration cadmium ratio below5mg·kg-1, descended when concentration cadmium ratio increasing to20mg·kg-1; in poor loam, soluble protein content displayed an downward trend with cadmium concentration increasing; glutathione, GSH and GSSG increasing linearly with cadmium concentration and GSH increased faster than GSSG in rich loam. Activity of related enzymes also changed with H2O2, GSH contents changing in rape body. In rich loam, CAT activity increased when concentration cadmium ratio below 5mg/kg, descended when concentration cadmium ratio increasing to20mg·kg-1, and its activity was obviously lower than that of rape in lean loam. In poor loam, CAT activity increased linearly with cadmium concentration; POD activity increased linearly with cadmium concentration in rich loam. In poor loam, POD activity grew when concentration cadmium ratio was below5mg·kg-1, then descended, and its activity was obviously higher than that of rape in rich loam; SOD activity increasing linearly with cadmium concentration in rich loam. SOD activity increased to maximum when concentration cadmium increased to20mg·kg-1; Both of GR and ATPS activity increased significantly in rape body, and GR activity of rape body increased more significantly in poor loam and ATPS activity of rape body increased more significantly in rich loam; GST activity increased linearly in rich loam and its activity increased to maximum in poor loam when concentration cadmium ratio increased to20mg·kg-1.3. Using soil pachycondyla method, concentration cadmium ratio in underground parts was greater than the earth parts and its ratio in poor loam was greater than in rich loam. Cadmium treatment with low concentration on rapeseed showed promoting action, but high concentration treatment on rapeseed showed inhibiting action. So the growth of rapeseed in rich loam was far better than that of in poor loam with cadmium concentration increasing. |
