Treatment | Light | Enhanced UV-B radiation | He-Ne laser irradiation | Dark culture |
CK | 8 h/d | - | - | 16 h/d |
B | 8 h/d | 8 h/d | - | 16 h/d |
L | 8 h/d | - | 2 min/d | 16 h/d |
BL | 8 h/d | 8 h/d | 2 min/d | 16 h/d |