Table 3. Comparison of the anatomical characteristics of Sonchus arvensis L. callus on dolomite media.
| Character | Control | Dolomite (mg/L) | ||||
|---|---|---|---|---|---|---|
| 50 | 75 | 100 | 150 | 200 | ||
| Callus type | Friable | Compact | Compact | Compact | Compact | Compact |
| Cell structure | Parenchyma (+++), meristem (+) | Parenchyma (++), meristem (++) | Parenchyma (+), meristem (++) | Parenchyma (+), meristem (+++) | Parenchyma (+), meristem (+++), schelenchyma (+) | Parenchyma (+), meristem (+++), schelenchyma (++) |
| Thickening of Cell wall | − | + | ++ | +++ | +++ | ++++ |
| Cell density | Not solid | Solid (+) | Solid (++) | Solid (++) | Solid (+++) | Solid (++++) |
| Somatic embryo | Globular stage (+) | Globular stage (++) | Globular stage (+) and heart stage (+) | Globular stage (+) and heart stage (++), and torpedo stage (+) | Globular stage (+), heart stage (+), and torpedo stage (+) | Globular stage (+), heart stage (++), and torpedo stage (++) |
| Secondary metabolite | − | − | + | ++ | +++ | ++++ |
Note: Control: callus under 2,4-D (1 mg/L) + BAP (0.5 mg/L) treatment; -: no characters appearance; +: degree of characters appearances.