Table 3.
Estimated contribution of organic and inorganic ions to leaf osmotic potential (Ψs ±SEM)
| Leaf OP | Na+ | Cl– | K+ | Sucrose (MPa) | Glucose | Fructose | Betaine | Proline | Inorganic contribution | Organic contribution ( %) | Total | |
| Hydroponic experiment (49 d after germination) | ||||||||||||
| WI4262 | –2.88±0.23 | –0.81 | –0.88 | –0.85 | –0.02 | –0.01 | –0.01 | –0.01 | –0.05 | 88 | 3 | 92 |
| Capstan | –2.65±0.21 | –0.78 | –0.81 | –0.75 | –0.03 | –0.05 | –0.01 | –0.02 | –0.06 | 88 | 6 | 95 |
| Fleet | –2.85±0.20 | –0.85 | –0.7 | –0.81 | –0.05 | –0.03 | –0.04 | –0.008 | –0.11 | 83 | 8 | 91 |
| Flagship | –2.87±0.21 | –0.86 | –0.85 | –0.71 | –0.05 | –0.06 | –0.04 | –0.02 | –0.05 | 84 | 8 | 92 |
| Schooner | –2.57±0.25 | –0.83 | –0.85 | –0.75 | –0.02 | –0.02 | –0.01 | –0.005 | –0.04 | 95 | 4 | 98 |
| Maritime | –2.61±0.26 | –0.85 | –0.79 | –0.75 | –0.05 | –0.02 | –0.01 | –0.008 | –0.05 | 92 | 5 | 97 |
| Pot experiment EC 7.2 Harvest 3 (70 d after germination) | ||||||||||||
| WI4262 | –1.28±0.03 | –0.18 | –0.22 | –0.38 | –0.09 | –0.06 | –0.09 | –0.11 | –0.03 | 61 | 30 | 91 |
| Capstan | –1.38±0.05 | –0.15 | –0.19 | –0.44 | –0.11 | –0.09 | –0.08 | –0.12 | –0.05 | 57 | 33 | 89 |
| Fleet | –1.21±0.04 | –0.16 | –0.21 | –0.40 | –0.12 | –0.10 | –0.11 | –0.05 | –0.02 | 64 | 33 | 97 |
| Flagship | –1.59±0.06 | –0.35 | –0.42 | –0.31 | –0.08 | –0.05 | –0.04 | –0.01 | –0.06 | 68 | 15 | 83 |
| Schooner | –1.58±0.08 | –0.48 | –0.50 | –0.31 | –0.02 | –0.05 | –0.02 | –0.02 | –0.02 | 82 | 8 | 90 |
| Maritime | –1.66±0.09 | –0.52 | –0.65 | –0.32 | –0.05 | –0.02 | –0.01 | –0.002 | –0.01 | 90 | 6 | 95 |
| Pot experiment EC 15.3 Harvest 3 (70 d after germination) | ||||||||||||
| WI4262 | –1.32±0.03 | –0.18 | –0.31 | –0.29 | –0.07 | –0.09 | –0.11 | –0.15 | –0.05 | 59 | 36 | 95 |
| Capstan | –1.65±0.05 | –0.21 | –0.29 | –0.35 | –0.11 | –0.09 | –0.10 | –0.18 | –0.11 | 52 | 36 | 87 |
| Fleet | –1.29±0.06 | –0.21 | –0.28 | –0.25 | –0.15 | –0.08 | –0.09 | –0.15 | –0.05 | 57 | 40 | 98 |
| Flagship | –2.25±0.08 | –0.49 | –0.59 | –0.35 | –0.11 | –0.13 | –0.15 | –0.01 | –0.02 | 64 | 19 | 82 |
| Schooner | –1.88±0.09 | –0.48 | –0.51 | –0.45 | –0.05 | –0.08 | –0.05 | –0.04 | –0.05 | 77 | 14 | 91 |
| Maritime | –2.11±0.08 | –0.60 | –0.71 | –0.35 | –0.04 | –0.05 | –0.04 | –0.05 | –0.05 | 79 | 11 | 90 |
| Field experiment (ZGS 65) | ||||||||||||
| WI4262 | –1.15±0.05 | –0.25 | –0.21 | –0.28 | –0.05 | –0.08 | –0.09 | –0.05 | –0.09 | 64 | 31 | 96 |
| Capstan | –1.21±0.09 | –0.22 | –0.25 | –0.31 | –0.08 | –0.05 | –0.05 | –0.02 | –0.11 | 64 | 26 | 90 |
| Fleet | –1.18±0.11 | –0.15 | –0.23 | –0.25 | –0.11 | –0.07 | –0.07 | –0.05 | –0.12 | 53 | 36 | 89 |
| Flagship | –1.45±0.10 | –0.33 | –0.4 | –0.25 | –0.05 | –0.08 | –0.05 | –0.07 | –0.08 | 68 | 23 | 90 |
| Schooner | –1.62±0.15 | –0.45 | –0.51 | –0.25 | –0.02 | –0.05 | –0.05 | –0.09 | –0.08 | 75 | 18 | 93 |
| Maritime | –1.65±0.13 | –0.49 | –0.55 | –0.22 | –0.05 | –0.08 | –0.05 | –0.08 | –0.05 | 76 | 19 | 95 |
The contribution of individual solutes to measured Ψs was determined using the van’t Hoff equation, where the calculated Ψs, was based on solute concentration on a fresh weight basis. The percentage value is based on the measured value of leaf Ψs.