| Aiming at the problem that microbe promote phytoremediation of Cd-contaminated soils, taking naturally contaminated soil (the contend of cd is 3 mg·kg-1) as experimental soil, rape as experimental plant, and inoculate microbe(JA1,JA2,JA3,JA4 strain) which could produce low-molecular organic acids to Cd-contaminated soils. A pot experiment was carried out to study the effects of four microbial strains (JA1,JA2,JA3,JA4 ) on cadmium uptake by rape in five cell concentration. The main findings is as follows:1. Based on morphological characteristics, four strains were primarily judge as bacterial colony. Strains JA1, JA2, JA3, JA4 were primarily identified as Listeria denitrificans, Bacillus cirallans, Neisseria sicca and Listeria grayi respectively by common bacterial identification manual.2. After microbial inoculation , rape could grow normally in each treatment, with no obvious toxic phenomenon. Average fresh weight and length of rape in 5 concentration of JA1,JA2,JA4treatment were higher than comparison (control) , that reached significant level. And compared with comparison, the biomass of rape promoted, accounting for 17.4%,28.1%,32.2%.The concentration of 4 kinds of strains effected the growth of rape. JA1,JA2,JA4 treatments showed a trend from ascent to descent, JA3 treatment showed a trend of decreasing.3. Concentrations of Cd in shoot of rape in JA1,JA2,JA4 treatments increased by 10.2%～36.1%,41.4%～57.4%,55.0%～69.7% compared with the control (CK). However , Concentrations of Cd in shoot of rape in JA3 treatment decreased by 1.9%～24.0%. Concentrations of Cd in root of rape in each treatments was about 1.51 to 2.60 times than shoot. The results showed that strains JA1, JA2, JA4 promoted uptake Cd in soil by rape, and strain JA3 had an affect of bio-stabilizing in to contaminated soil that Cd concentration was 3.1mg·kg-1.4. The amounts of Cd extracted by plants were increased by 49.0%,90.2%,117.6% in JA1,JA2,JA4 treatments respectively, while decreased by 11.8% in JA3 treatment. 4 kinds of strains effected the amounts of Cd extracted by plants , JA1,JA2 treatments showed a trend from ascent to descent, JA3 treatment showed a trend of decreasing, JA4 treatment showed a trend of increasing.5. JA1,JA2,JA4 treatments, the contents of available Cd increased significantly in soil, and increased by 25.9%,59.3% and 41.9% compared with control; The contents of available Cd decreased by 13.6% in JA3 treatment.6. pH of The control was 8.45, In the JA1,JA2,JA3,JA4 treatments, the average of soil pH respectively decreased 0.39,0.53,0.47 and 0.62 unit. The results indicated that microorganisms can decrease soil pH to some extent.7. The content of chlorophyll were higher than the control, by adding microorganisms. JA1,JA2,JA3,JA4 treatments were respectively 2.1,3.9,1.2 and 2.3 unit higher than the control. The content of soluble protein were 3.61, 3.50, 3.64, 3.37 mg·g-1, and were 3.4%～11.7% higher than the control. JA1,JA2,JA3 treatments the content of Vc were 40.3, 37.6, 40.0 mg·kg-1, and were 26.3%, 24.1% and 25.4% respectively higher than the control; but JA4 treatment the content of Vc decreased by 10.3%. Therefore, except some treatments, quality of rape was not affected with microorganisms addition .
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