Table 2.
Changes in leaf water relations and osmotic adjustment under drought stress and re-watering conditions during tillering and jointing growth stages of two wheat cultivars. The measurements were made at last day of drought stress and three days after re-watering.
| Stress stages | Tillering | Jointing | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Water levels | SS | MS | WW | SS | MS | WW | ||||||
| Parameters | LH-7 | YM-16 | LH-7 | YM-16 | LH-7 | YM-16 | LH-7 | YM-16 | LH-7 | YM-16 | LH-7 | YM-16 |
| Ψw (−MPa) | 1.84b | 1.95a | 1.32d | 1.54c | 0.43e | 0.41e | 2.05b | 2.25a | 1.57d | 1.65c | 0.56e | 0.51e |
| Ψs (−MPa) | 2.56a | 2.37b | 1.87c | 1.75d | 1.25e | 1.26e | 2.45a | 2.33b | 2.05c | 1.96c | 1.43d | 1.41d |
| RWC (%) | 81.80d | 77.50e | 89.50b | 86.40c | 94.50a | 94.80a | 77.50c | 73.80d | 85.30b | 83.40b | 93.40a | 94.00a |
| Ψs100 (−MPa) | 2.09a | 1.88b | 1.65c | 1.57d | 1.18e | 1.19e | 1.89a | 1.74b | 1.71b | 1.63c | 1.33a | 1.32a |
| OA (MPa) | 0.91a | 0.75b | 0.51c | 0.40d | — | — | 0.56a | 0.47b | 0.41c | 0.30d | — | — |
| Re-watering | ||||||||||||
| Ψw (−MPa) | 0.81b | 0.89a | 0.53d | 0.61c | 0.43e | 0.43e | 1.10b | 1.17a | 0.74b | 0.78b | 0.57c | 0.56c |
| Ψs (−MPa) | 1.81a | 1.76a | 1.17b | 1.10c | 0.95d | 0.95d | 1.89a | 1.83a | 1.28b | 1.21b | 0.91c | 0.90c |
| RWC (%) | 91.10b | 87.90c | 93.50ab | 93.00ab | 94.50a | 94.70a | 86.50c | 84.70c | 92.30b | 91.50b | 93.10a | 93.80a |
| Ψs100 (−MPa) | 1.10ab | 1.17a | 1.03b | 1.02b | 0.93c | 0.91c | 1.63a | 1.55b | 1.18c | 1.13c | 0.84d | 0.84d |
| OA (MPa) | 0.65a | 0.62a | 0.19c | 0.16c | — | — | 0.73a | 0.70a | 0.33b | 0.29b | — | — |
Ψw: leaf water potential, Ψs: osmotic potential, Ψs100: turgor potential, RWC: relative water content. Severe (SS) and moderate (MS) drought stress were applied at tillering and jointing, respectively, and followed by re-watering. WW indicated well-watered treatment. The shaded area indicates the measurements taken following re-watering. The lower case letters following the data represent significant differences for the means of six replications (n = 6) under tillering and jointing stages, respectively, as measured by the Post hoc Test at P < 0.05 during each experiment season of 2014–2015 and 2015–2016.