Table 1.
Vaccinium corymbosum root anatomical data and hydraulic parameters for seven root orders
| Parameters | Units | Root order | ||||||
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | ||
| Measured parameters | ||||||||
| Root diametera | μm | 40 | 48 | 75 | 120 | 177 | 222 | – |
| Vessel diameterb | μm | 3.9 | 4.2 | 4.8 | 5.8 | 6.2 | 15.6 | 17.8 |
| Vessel number (nv)a | 13 | 12 | 22 | 28 | 39 | 501 | 802 | |
| Total root lengtha | m | 1.42 | 1.09 | 1.1 | 0.54 | 0.19 | 0.19 | 0.1 |
| Individual root lengtha | cm | 0. 15 | 0. 38 | 0. 81 | 0. 94 | 1.43 | 0. 98 | 1.15 |
| Number of roots per order (nr)a | 157 | 48 | 23 | 9 | 2 | 3 | 1 | |
| Calculated parameters | ||||||||
| Individual root conductance (Lx) | m3 s−1 MPa−1 | 5.3E-11 | 2.5E-11 | 3.7E-11 | 8.8E-11 | 1.0E-10 | 7.5E-08 | 1.7E-07 |
| Individual root resistance (Rx) | MPa s m−3 | 1. 9E+10 | 4.0E+10 | 2.7E+10 | 1.1E+10 | 9.7E+09 | 1.3E+07 | 5.7E+06 |
| Root resistance (Rt) | MPa s m−3 | 1.2E+08 | 8.3E+08 | 1.2E+09 | 1.2E+09 | 4.4E+09 | 4.1E+06 | 4.0E+06 |
| Estimated internal root Ψ at 20.00 h | MPa | –3.53 | –3.49 | –3.22 | –2.83 | –2.44 | –1.02 | –1.02 |
| Estimated internal root Ψ at 00.00 h | MPa | –2.57 | –2.55 | –2.42 | –2.23 | –2.04 | –1.36 | –1.35 |
| Estimated internal root Ψ at 05.00 h | MPa | –1.19 | –1.19 | –1.18 | –1.16 | –1.15 | –1.09 | –1.09 |
Root anatomical measurements were obtained from Valenzuela-Estrada et al. (2008). Root hydraulic parameters were estimated by the single-branch model. Individual root estimations for each root order are shown for conductance and resistance parameters (Lx and Rx), while other parameters are values of each root order taken as a group.
a
Average value.
b
Vessel diameter is expressed as the hydraulic weighted mean (see Materials and methods).