Table 1.
Comparison of biomass production of the nodulated W82 and DT2008 plants after growth for 21 days in vermiculite soil and exposure to drought stress and recovery treatments. Well-watered (WW) plants were irrigated every day, whereas drought stress (WS) was imposed by withholding water for either four (4 D) or seven (7 D) days. Recovery treatment was experienced by withholding water for seven days followed by a subsequent rewatering for three days (7 D + 3 W). Data presented are the means ± SE of four replicates. Asterisks indicate significant differences as determined by Student's t-test (* P < 0.05; ** P < 0.01; *** P < 0.001).
| Treatment | W82 | DT2008 | |||
|---|---|---|---|---|---|
| WW | WS | WW | WS | ||
| Fresh weight (g) | |||||
| Shoot | 4 D | 5.46 ± 0.42 | 3.72 ± 0.18** | 6.92 ± 0.48 | 6.06 ± 0.53 |
| 7 D | 6.64 ± 0.54 | 3.89 ± 0.18** | 9.94 ± 0.50 | 6.51 ± 0.39** | |
| 7 D + 3 W | 10.57 ± 0.61 | 7.10 ± 0.87* | 11.03 ± 0.58 | 7.31 ± 0.30** | |
| Root | 4 D | 2.32 ± 0.28 | 0.91 ± 0.09** | 2.58 ± 0.19 | 1.78 ± 0.09* |
| 7 D | 3.68 ± 0.13 | 1.64 ± 0.15*** | 4.11 ± 0.30 | 2.44 ± 0.33** | |
| 7 D + 3 W | 3.89 ± 0.22 | 2.31 ± 0.26** | 5.62 ± 0.33 | 4.23 ± 0.10** | |
| Nodules | 4 D | 0.44 ± 0.04 | 0.31 ± 0.03* | 0.61 ± 0.02 | 0.36 ± 0.04** |
| 7 D | 0.57 ± 0.05 | 0.27 ± 0.03** | 0.71 ± 0.07 | 0.31 ± 0.03** | |
| 7 D + 3 W | 0.68 ± 0.06 | 0.35 ± 0.06** | 0.55 ± 0.04 | 0.37 ± 0.02** | |
|
| |||||
| Dry weight (g) | |||||
| Shoot | 4 D | 0.74 ± 0.04 | 0.60 ± 0.03* | 1.16 ± 0.06 | 1.11 ± 0.09 |
| 7 D | 1.36 ± 0.10 | 0.77 ± 0.04** | 1.99 ± 0.10 | 1.30 ± 0.08** | |
| 7 D + 3 W | 2.11 ± 0.12 | 1.41 ± 0.18* | 2.21 ± 0.12 | 1.46 ± 0.06** | |
| Root | 4 D | 0.15 ± 0.02 | 0.06 ± 0.01** | 0.18 ± 0.02 | 0.12 ± 0.01* |
| 7 D | 0.17 ± 0.01 | 0.07 ± 0.01*** | 0.21 ± 0.02 | 0.12 ± 0.02** | |
| 7 D + 3 W | 0.23 ± 0.01 | 0.14 ± 0.02** | 0.34 ± 0.02 | 0.25 ± 0.01** | |