Using radiation to enhance quality attributes of leafy vegetables: a mini-review

Q. Meng, E.S. Runkle
The radiation spectrum, photon flux density, and photoperiod play essential roles in plant growth and development. The emergence of light-emitting diodes (LEDs) in plant science has advanced our understanding of how the radiation spectrum regulates primary and secondary metabolism in plants. It is particularly important for leafy vegetables grown in controlled environments because it manipulates plant growth and quality attributes such as appearance, texture, nutrition, and flavor. Red- and far-red-absorbing phytochromes and blue-absorbing cryptochromes mediate the shade-avoidance response and phototropism to regulate plant morphological traits such as plant height and leaf area. Ultraviolet-A, ultraviolet-B, and blue radiation can activate protective mechanisms in plants, thereby increasing accumulation of health-promoting phytonutrients including antioxidants, flavonoids, and carotenoids. Supplemental blue radiation increases anthocyanin production in leaves for enhanced red coloration. In addition, combinations of various wavebands can influence organoleptic properties (e.g., flavor and aroma) of leafy vegetables through radiation-regulated biosynthesis of phytochemicals and volatiles. The radiation spectrum can also interact with other environmental factors such as photon flux density, creating a complex network of physiological and biochemical regulation. As consumers of leafy vegetables prioritize food quality in their purchasing behaviors, precise delivery of radiation from LEDs presents opportunities to consistently produce high-quality indoor edible crops with traits of interest.
Meng, Q. and Runkle, E.S. (2018). Using radiation to enhance quality attributes of leafy vegetables: a mini-review. Acta Hortic. 1227, 571-578
DOI: 10.17660/ActaHortic.2018.1227.72
anthocyanin, LEDs, nutritional value, sensory attributes

Acta Horticulturae