Table 2.
Callus induction percentage of P. bullata from leaf and midrib explants cultured on woody plant medium (WPM) containing different types and concentrations of auxins under light and dark conditions.
| Light Condition | |||||||||
| Plant Growth Regulators (PGRs) | Leaf Explants | Midrib Explants | |||||||
| Adaxial | Abaxial | ||||||||
| Callus Induction Percentage | Induction Time (Days) | Callus Morphology | Callus Induction Percentage | Induction Time (Days) | Callus Morphology | Callus Induction Percentage | Induction Time (Days) | Callus Morphology | |
| 0 | - | - | - | - | - | - | - | - | - |
| 9.05 µM 2,4-D | - | - | - | - | - | - | - | - | - |
| 18.10 µM 2,4-D | 2.22 d | 101 | Compact | - | - | - | - | - | - |
| 27.14 µM 2,4-D | - | - | - | - | - | - | 2.22 d | 111 | Compact |
| 36.19 µM 2,4-D | - | - | - | - | - | - | - | - | - |
| 45.24 µM 2,4-D | - | - | - | - | - | - | - | - | - |
| 8.28 µM picloram | - | - | - | - | - | - | 11.11 cd | 82 | Friable |
| 16.56 µM picloram | 2.22 d | 90 | Friable | - | - | - | - | - | - |
| 24.85 µM picloram | - | - | - | 4.34 d | 80 | Friable | - | - | - |
| 33.13 µM picloram | 2.22 d | 78 | Friable | 4.34 d | 76 | Friable | 2.22 d | 67 | Friable |
| 41.41 µM picloram | - | - | - | - | - | - | - | - | - |
| 10.74 µM NAA | - | - | - | - | - | - | - | - | - |
| 21.48 µM NAA | - | - | - | - | - | - | - | - | - |
| 32.22 µM NAA | - | - | - | - | - | - | - | - | - |
| 42.96 µM NAA | - | - | - | - | - | - | - | - | - |
| 53.70 µM NAA | - | - | - | - | - | - | 2.22 d | 90 | Friable |
| 9.05 µM dicamba | - | - | - | - | - | - | - | - | - |
| 18.10 µM dicamba | - | - | - | - | - | - | - | - | - |
| 27.14 µM dicamba | - | - | - | - | - | - | - | - | - |
| 36.19 µM dicamba | - | - | - | - | - | - | - | - | - |
| 45.24 µM dicamba | - | - | - | - | - | - | - | - | - |
| Dark Condition | |||||||||
| Plant Growth Regulators (PGRs) | Leaf Explants | Midrib Explants | |||||||
| Adaxial | Abaxial | ||||||||
| Callus Induction Percentage | Induction Time (Days) | Callus Morphology | Callus Induction Percentage | Induction Time (Days) | Callus Morphology | Callus Induction Percentage | Induction Time (Days) | Callus Morphology | |
| 0 | - | - | - | - | - | - | - | - | - |
| 9.05 µM 2,4-D | 2.22 d | 117 | Compact | 13.33 cd | 117 | Compact | 15.55 bcd | 117 | Friable |
| 18.10 µM 2,4-D | - | - | - | 4.34 d | 102 | Compact | 4.34d | 102 | Friable |
| 27.14 µM 2,4-D | - | - | - | - | - | - | - | - | - |
| 36.19 µM 2,4-D | - | - | - | - | - | - | - | - | - |
| 45.24 µM 2,4-D | - | - | - | - | - | - | - | - | - |
| 8.28 µM picloram | 2.22 d | 100 | Friable | - | - | - | 11.11 cd | 100 | Friable |
| 16.56 µM picloram | - | - | - | - | - | - | 53.33 a | 78 | Friable |
| 24.85 µM picloram | - | - | - | - | - | - | 13.33 cd | 80 | Friable |
| 33.13 µM picloram | - | - | - | - | - | - | - | - | - |
| 41.41 µM picloram | - | - | - | - | - | - | - | - | - |
| 10.74 µM NAA | - | - | - | - | - | - | 4.34 d | 103 | Friable |
| 21.48 µM NAA | - | - | - | - | - | - | - | - | - |
| 32.22 µM NAA | - | - | - | - | - | - | - | - | - |
| 42.96 µM NAA | - | - | - | - | - | - | - | - | - |
| 53.70 µM NAA | - | - | - | - | - | - | - | - | - |
| 9.05 µM dicamba | - | - | - | - | - | - | - | - | - |
| 18.10 µM dicamba | - | - | - | - | - | - | - | - | - |
| 27.14 µM dicamba | - | - | - | - | - | - | - | - | - |
| 36.19 µM dicamba | - | - | - | - | - | - | - | - | - |
| 45.24 µM dicamba | - | - | - | - | - | - | - | - | - |
Different letters indicate the values of significant difference at p ≤ 0.05 Tukey’s range test for light and dark conditions. (-) = no response.