Table I. Solar UV-B effects on cell division and cell expansion parameters.
Average values (n = 5) and corresponding se are shown. NS, Not significant.
| Growth Parameters | Control | UV-B | UV-B/C Ratio | Student’s t Test |
|---|---|---|---|---|
| Final leaf length (cm) | 46.1 ± 4.5 | 40.0 ± 5.7 | 0.87 | 0.02 |
| Leaf elongation rate (mm h−1) | 2.7 ± 0.3 | 1.9 ± 0.6 | 0.70 | 0.009 |
| Mature cell size (μm) | 121 ± 18 | 122 ± 8 | 1.01 | NS |
| Cell production (cells h−1) | 24 ± 4 | 15 ± 5 | 0.63 | 0.010 |
| DEZ size (mm) | 38 ± 4 | 25 ± 2 | 0.65 | <0.001 |
| Size of cells leaving the DEZ (μm) | 76 ± 15 | 67 ± 20 | 0.88 | NS |
| No. of cells in the DEZ | 1,614 ± 338 | 965 ± 196 | 0.60 | 0.002 |
| Cell cycle duration (h) | 46 ± 5 | 46 ± 12 | 1.00 | NS |
| Average cell division rate (μm μm−1 h−1) | 0.030 ± 0.007 | 0.016 ± 0.008 | 0.54 | 0.035 |
| Residence time in the EZ (h) | 17 ± 4 | 30 ± 9 | 1.79 | 0.006 |
| GZ size (mm) | 81 ± 8 | 69 ± 10 | 0.84 | 0.04 |
| No. of cells in the GZ | 2,030 ± 440 | 1,413 ± 293 | 0.69 | 0.02 |
| Residence time in the DEZ (h) | 489 ± 60 | 454 ± 112 | 0.93 | NS |
| No. of cells in the EZ | 415 ± 137 | 448 ± 144 | 1.07 | NS |
| EZ size (mm) | 44 ± 9 | 44 ± 9 | 1.01 | NS |
| Average cell expansion rate (μm μm−1 h−1) | 0.028 ± 0.009 | 0.023 ± 0.012 | 0.83 | NS |