Table 1.
Calculations of Sieve Tube–Specific Conductivity
| Species | Pore Radius rp (μm) for Average Calculations | Number of Pores per Plate Np | Length of Sieve Element l (μm) | Length of Sieve Plate lp (μm) | Radius of Sieve Plate r (μm) | k (μm2) Based on Average Pore Size | k (μm2) Based on Individual Pore Sizes |
| Cucurbita | 2.54 ± 0.86 | 54.8 ± 11.9 | 341 ± 77 | 1.27 ± 0.29 | 25.65 ± 2.97 | 24.42 | 53.00 |
| Phaseolus | 0.73 ± 0.24 | 95.4 ± 31.7 | 140 ± 38 | 0.43 ± 0.11 | 10.13 ± 1.13 | 2.77 | 6.33 |
| Solanum | 0.61 ± 0.15 | 121.3 ± 30.3 | 130 ± 90 | 0.52 ± 0.12 | 10.70 ± 1.4 | 1.71 | 3.82 |
| Ricinus | 0.52 ± 0.14 | 371.9 ± 79 | 255 ± 122 | 0.24 ± 0.05 | 16.22 ± 1.6 | 3.52 | 10.57 |
| Phyllostachys | 0.61 ± 0.13 | 104.0 ± 12.7 | 1052 ± 244 | 0.39 ± 0.1 | 11.60 ± 1.0 | 8.25 | 12.44 |
| Nicotianaa | 0.35 | 108 | 122 | 1.2 | 5.5 | 0.45 | |
| Arabidopsisa | 0.26 | 52 | 107 | 1.0 | 2.0 | 0.28 |
Values were measured based on scanning electron microscopy images with the exception of l in Phyllostachys, which was measured by fluorescence microscopy. Calculations based on average pore sizes were in all cases significantly lower compared with calculations based on individual pores (error indicates se).
a
Values and calculations for Nicotiana and Arabidopsis were taken from Thompson and Wolniak (2008).