Table 5.
Axial and radial hydraulic conductivity [(m s−1 MPa−1)×10−8] of seminal and adventitious roots of hydroponically grown barley plants
| Conductivity | Root | Hydrostatically induced water flow |
Osmotically induced water flow |
|||||
| Root pressure probe | Vacuum perfusion | Mean (range) | Root pressure probe | Vacuum perfusion | Exudation | Mean (range) | ||
| Axial | Seminal | 548±266a | 4480±790b | 2514 (548–4480) | – | – | – | – |
| Adventitious | 93±112c | – | 93 | – | – | – | – | |
| Radial | Seminal | 13.2±3.0a,b,c | 20.0±3.7b | 16.6 (13.2–20) | 5.4±2.0e | 25.3 ±10.3a,b | 11.8±1.8a,f | 14.1 (5.4–25.3) |
| Adventitious | 16.0±11.7a,b,c | – | 16.0 | 7.3 ±3.4c,e,f | – | 5.4±0.6d | 6.3 (5.4–7.3) | |
Conductivity was calculated by relating values of conductance shown in Table 4 to root surface area. The surface area ranged from 4.9 to 5.5×10−4 m2 in seminal and 1.2 to 1.5×10−4 m2 in adventitious roots. Conductivity is given as means±SD of three root analyses; the range of values is given in brackets ‘(min–max)’, together with the overall mean.
Statistical significance of difference in axial, or in radial conductance between types of root and experimental approach is indicated by different superscripts (P≤0.05, Student's t-test); ‘–’, not measured, or not applicable.