Table 5. Colony forming units of Cupriavidus metallidurans CH34 by milligram of fresh weight (CFU mg−1 FW) of plant, agar surrounding plant (rhizosphere), and non-planted MS1/2 agar medium (non-rhizosphere).
| Treatment | Plant (CFU mg−1FW) | Rhizosphere (CFU mg−1FW) | Non-rhizosphere (CFU mg−1FW) |
|---|---|---|---|
| MS(1/2) | 5.8 × 108 ± 4.7 × 108a | 1.0 × 107 ± 8.5 × 106a | 1.7 × 104 ± 1.1 × 104a |
| MS(1/2) + 50 µM Cu2+ | 1.8 × 109 ± 7.5 × 107a | 1.4 × 106 ± 1.2 × 106b | 3.6 × 104± 1.3 × 104b |
Notes.
C. metallidurans CH34 CFU mg−1 FW were counted in 21 days after sowing plants, rhizosphere agar and non-rhizosphere MS1/2 agar, in 0 and 50 µM CuSO4x5H2O treatments. Plants were initially inoculated with 1.0 × 104 CFU ml−1. The average values of 15–20 replicates and their respective standard deviations are shown. FW corresponds to that of plant or agar material. Different letters in same column indicate statistically significant differences according to a t-test, p < 0.05.