Table 3. The rhizosphere soil densities of rhizobacterias inoculated in the potted soil of transgenic Bt maize and its parental line of non-Bt maize grown under ambient and elevated CO2 in 2016 and 2017.
| Measure matters | Rhizobacteria infections | 2016 (AB; AC copies/g) | 2017 (AB; AC copies/g) | |
|---|---|---|---|---|
| Sampled soil before maize planting | 5.53 ± 0.24 105; 4.47 ± 0.12 105 | 5.61 ± 0.11 105; 4.33 ± 0.17 105 | ||
| Sampled soil at the maize seedling after 14 days | AB | aCO2-Bt | 8.46 ± 0.24 1011; 4.48 ± 0.26 105 | 8.40 ± 0.28 1011; 4.44 ± 0.11 105 |
| aCO2-Xy | 8.25 ± 0.26 1011; 4.21 ± 0.08 105 | 8.69 ± 0.23 1011; 4.56 ± 0.22 105 | ||
| eCO2-Bt | 8.36 ± 0.19 1011; 4.43 ± 0.15 105 | 8.59 ± 0.21 1011; 4.47 ± 0.17 105 | ||
| eCO2-Xy | 8.70 ± 0.27 1011; 4.58 ± 0.29 105 | 8.24 ± 0.12 1011; 4.34 ± 0.27 105 | ||
| AC | aCO2-Bt | 5.54 ± 0.25 105; 7.37 ± 0.29 1011 | 5.70 ± 0.28 105; 7.40 ± 0.26 1011 | |
| aCO2-Xy | 5.73 ± 0.24 105; 7.29 ± 0.17 1011 | 5.36 ± 0.22 105; 7.66 ± 0.25 1011 | ||
| eCO2-Bt | 5.62 ± 0.30 105; 7.71 ± 0.15 1011 | 5.13 ± 0.04 105; 7.32 ± 0.13 1011 | ||
| eCO2-Xy | 5.46 ± 0.28 105; 7.59 ± 0.17 1011 | 5.42 ± 0.13 105; 7.57 ± 0.22 1011 | ||
| CK | aCO2-Bt | 5.71 ± 0.20 105; 4.52 ± 0.21 105 | 5.92 ± 0.08 105; 4.67 ± 0.17 105 | |
| aCO2-Xy | 5.50 ± 0.29 105; 4.24 ± 0.15 105 | 5.33 ± 0.18 105; 4.31 ± 0.13 105 | ||
| eCO2-Bt | 5.46 ± 0.08 105; 4.26 ± 0.18 105 | 5.62 ± 0.31 105; 4.48 ± 0.21 105 | ||
| eCO2-Xy | 5.46 ± 0.18 105; 4.76 ± 0.23 105 | 5.47 ± 0.17 105; 4.21 ± 0.09 105 | ||
| Sampled soil at the maize harvest | AB | aCO2-Bt | 8.50 ± 0.19 1011b; 4.65 ± 0.21 105 | 8.39 ± 0.26 1011b; 4.01 ± 0.26 105 |
| aCO2-Xy | 8.44 ± 0.15 1011b; 4.11 ± 0.23 105 | 8.65 ± 0.19 1011b; 4.30 ± 0.18 105 | ||
| eCO2-Bt | 9.81 ± 0.23 1011a; 4.13 ± 0.17 105 | 1.09 ± 0.04 1012a; 4.67 ± 0.20 105 | ||
| eCO2-Xy | 9.98 ± 0.25 1011a; 4.49 ± 0.22 105 | 1.02 ± 0.03 1012a; 4.89 ± 0.23 105 | ||
| AC | aCO2-Bt | 5.57 ± 0.31 105; 7.27 ± 0.26 1011b | 5.40 ± 0.08 105; 7.30 ± 0.14 1011b | |
| aCO2-Xy | 5.99 ± 0.25 105; 7.49 ± 0.19 1011b | 4.97 ± 0.15 105; 7.24 ± 0.19 1011b | ||
| eCO2-Bt | 4.89 ± 0.27 105; 8.98 ± 0.15 1011a | 5.94 ± 0.14 105; 9.07 ± 0.12 1011a | ||
| eCO2-Xy | 5.33 ± 0.10 105; 8.96 ± 0.21 1011a | 5.77 ± 0.12 105; 9.03 ± 0.18 1011a | ||
| CK | aCO2-Bt | 5.15 ± 0.35 105; 4.65 ± 0.23 105 | 5.39 ± 0.08 105; 4.56 ± 0.22 105 | |
| aCO2-Xy | 5.49 ± 0.19 105; 4.37 ± 0.33 105 | 4.97 ± 0.16 105; 4.66 ± 0.15 105 | ||
| eCO2-Bt | 5.59 ± 0.14 105; 4.76 ± 0.11 105 | 4.88 ± 0.25 105; 4.64 ± 0.17 105 | ||
| eCO2-Xy | 5.12 ± 0.14 105; 4.69 ± 0.05 105 | 5.13 ± 0.13 105; 4.24 ± 0.10 105 | ||
Note:
Rhizobacteria infections: A. brasilense (AB) and A. chroococcum (AC) vs. the control buffer solution (CK). CO2 levels: ambient CO2 (aCO2) and elevated CO2 (eCO2). Transgenic treatment: Bt maize (Bt) and non-Bt maize (Xy). Different lowercase letters indicate significantly different between ambient CO2 and elevated CO2 for same maize cultivar in same year by the Duncan test at P < 0.05, respectively.