Blue and red light-emitting diodes improve the growth and physiology of in vitro-grown carnations 'Green Beauty' and 'Purple Beauty'

The objective of this study was to determine the effect of light quality on the growth, physiology, and antioxidant enzyme activity of two important domestic carnation (Dianthus caryophyllus) cultivars: 'Green Beauty' and 'Purple Beauty'. In vitro-grown shoot tip explants were cultured on the plant growth regulator (PGR)-free Murashige and Skoog (MS) medium under a conventional cool white fluorescent lamp (control), blue light-emitting diode (LED), or red LED. Growth traits, photosynthetic and biochemical parameters, activity of antioxidant enzymes, and nutrient content were measured after 8 weeks. Interestingly, the blue and red LED treatments resulted in a significant increase in growth, photosynthetic parameters, and nutrient content in comparison to the conventional cool white florescent lamp treatment. In addition, red LED treatment increased the activities of antioxidant enzymes and elemental contents in both cultivars. Thus, incorporating blue or red LED treatments enhances the quality of 'Green Beauty' and 'Purple Beauty' carnations propagated in vitro.