Table 3.
Anatomical characteristics of the petiole of the five Ulmus species.
| Parameters | U. davidiana var. japonica | U. parvifolia | U. macrocarpa | U. laciniata | U. pumila |
|---|---|---|---|---|---|
| Width of epidermal cells in adaxial part (μm) | 16.4 ± 1.2 ab | 15.5 ± 0.7 b | 18.8 ± 3.2 a | 18.3 ± 5.0 a | 13.5 ± 1.0 c |
| Length of epidermal cells in adaxial part (μm) | 14.4 ± 1.6 a | 9.3 ± 0.5 b | 13.9 ± 1.3 a | 16.6 ± 4.1 a | 9.4 ± 1.1 b |
| Width of epidermal cells in abaxial part (μm) | 15.2 ± 2.1 b | 16.1 ± 0.4 b | 21.5 ± 3.2 a | 24.7 ± 3.5 a | 14.0 ± 2.2 b |
| Length of epidermal cells in abaxial part (μm) | 13.5 ± 2.3 b | 12.5 ± 0.4 b | 15.1 ± 2.5 ab | 19.4 ± 3.1 a | 10.2 ± 1.2 c |
| Diameter of collenchyma cells (μm) | 22.2 ± 0.7 c | 17.7 ± 5.5 c | 31.5 ± 2.2 b | 37.3 ± 2.3 a | 17.9 ± 2.3 c |
| Diameter of parenchyma cells in cortex (μm) | 20.3 ± 1.5 a | 14.2 ± 3.3 b | 17.5 ± 0.6 ab | 22.3 ± 5.5 a | 16.8 ± 1.9 ab |
| Diameter of parenchyma cells in pith (μm) | 29.1 ± 1.9 c | 23.5 ± 1.1 d | 38.6 ± 2.4 b | 42.9 ± 1.7 a | 26.7 ± 3.7 cd |
| Ratio of vascular bundle thickness to petiole diameter * | 0.08 ± 0.01 b | 0.10 ± 0.01 a | 0.07 ± 0.01 b | 0.07 ± 0.01 b | 0.11 ± 0.02 a |
| Ratio of vascular bundle width to vascular bundle height * | 0.71 ± 0.03 c | 1.03 ± 0.02 a | 0.94 ± 0.05 b | 0.80 ± 0.09 c | 0.94 ± 0.01 b |
Data are expressed as mean ± SD (n > 3) of five independent experiments. Different upper letters in the same line indicate a significant difference (p < 0.05) among samples. * Ratio of vascular bundle thickness to petiole diameter, and ratio of vascular bundle width to vascular bundle height were calculated from a/b and c/d, respectively, in Figure 3.