Table II.
The dimensions and hydraulic properties of detached root segments at 14 d after sowing
Root segments, excised from the taproot of lupin or the longest seminal root of wheat, were connected to a root pressure probe. When Pr was stable, the Lr was measured. Lr was normalized by dividing by the surface area of the root to give Lpr. Because of the dependence of some hydraulic parameters on root length (see text for details), ranges are given with means ± se in parentheses. Asterisks denote significant differences between species (P < 0.001).
| Property | Narrow-Leafed Lupin | Yellow Lupin | Wheat |
|---|---|---|---|
| Diameter (mm)a | 1.1–1.9 | 0.7–1.3 | 0.5–0.9 |
| (1.5 ± 0.05*) | (1.0 ± 0.03*) | (0.7 ± 0.03*) | |
| Length (mm) | 75–181 | 82–170 | 69–179 |
| (129 ± 6) | (120 ± 5) | (120 ± 8) | |
| No. of cortical cell layers (including endodermis) | 9–11 | 8–10 | 5–7 |
| Pr (kPa) | 20–119 | 26–103 | 77–172 |
| (48.5 ± 5.1) | (52.8 ± 3.4) | (114.9 ± 7.3*) | |
| Lr (m3 s−1 MPa−1 × 10−11) | 2.0–7.0 | 1.4–3.6 | 1.2–4.1 |
| (3.8 ± 0.3*) | (2.3 ± 0.1) | (2.5 ± 0.2) | |
| Lpr (m s−1 MPa−1 × 10−8) | 3.7–8.6 | 3.8–8.9 | 5.3–18.4 |
| (6.0 ± 0.4) | (5.9 ± 0.3) | (10.6 ± 1.0*) | |
| No. of measured roots | 20 | 22 | 17 |
a
Diameter was measured at the excised end of the root.