Effects Of CCC On Soybean Nutrients Uptake And Resistance Under Zinc And Chromium Combined Stress

In this controlled pot experiment, two varieties of soybean (Ribenqing and Hanguosanqingdou) were chosen to be the test materials and purple soil which was polluted by zinc and chromium was chosen to be the test soil, chlormequat chloride (CCC) was chosen to treat by seed soaking and foliar spraying in initial flower stage and6concentration gradients were set as follows:0g/L (CK),0.50g/L,0.75g/L,1.00g/L,1.50g/L and2.00g/L. According to the principle of completely randomized experiment,22treatments in total, each repeated5times, a total of110pots. The experiment researched the effects of nutrients availability in rhizosphere soil, nutrients content in plants, antioxidant enzyme activity, MDA content, soluble sugar and soluble protein content in seed filling stage, content of nutrients, zinc and chromium in grains and the biomass in maturity by CCC which were treated by two kinds of methods and different concentrations systematically in order to offer a new thought for the safety production of soybean in soil which were polluted by zinc and chromium. The main results were as follows:1. Soaking and spraying CCC increased the content of N, P, K in two varieties of plants and the available nutrients content in rhizosphere soil under zinc and chromium combined stress in seed filling stage. Overall, effects of increasing available nutrients content in rhizosphere soil were much better when sprayed and soaked with0.75g/L,1.00g/L, and effects of P content in plants were much better when sprayed with1.00g/L and soaked with0.50g/L,0.75g/L, effects of K content in plants were much better when sprayed and soaked with1.00g/L, this result provided basis for the increase of nutrients content and biomass in grains in maturity.2. MDA content in plants were decreased more effectively when sprayed with0.75g/L,1.00g/L under zinc and chromium combined stress in seed filling stage, but MDA content were increased by high-concentrations. The content of soluble sugar and soluble protein were increased by soaking and spraying, showed the trend that increased at first and then reduced with the increase of CCC concentrations by spraying and expressed some differences by soaking.3. oaking and spraying CCC increased the activity of SOD, POD and CAT in two varieties of plants under zinc and chromium combined stress in seed filling stage, and showed the trend that increased at first and then reduced with the increase of CCC concentration about POD and CAT activity. Effects of POD activity were much better when sprayed and soaked with1.00g/L, and effects of CAT activity were much better when sprayed with1.00g/L,1.50g/L by spraying and soaked with0.75g/L,1.00g/L4. Soaking and spraying CCC increased the content of N, P, K and the biomass in grains in two varieties of soybean under zinc and chromium combined stress in maturity, and the effects were much better when sprayed with1.00g/L,1.50g/L and soaked with0.75g/L,1.00g/L. Soaking and spraying CCC decreased zinc and chromium content in maturity, and the effects were much better when sprayed with0.75g/L and soaked with0.50g/L.The significative research showed that the nutrients content and biomass were increased while the zinc and chromium content were decreased through the increase of the resistance of plants by soaking and spraying CCC under zinc and chromium combined stress.