REGULATING RADIATION QUALITY AND INTENSITY USING NARROW-BAND LEDS FOR OPTIMIZATION OF SOMATIC EMBRYOGENESIS

Abstract

The objectives of this study were to examine and optimize how radiation quality andintensity influenced both the induction and development of somatic embryos from carrot embryogeniccalli using light-emitting diodes (LEDs), which emit precise narrow-band radiation. Somatic embryosinduced from carrot embryogenic calli were exposed for 14 days to red and blue radiation at variouslight intensities. The results pertaining to somatic embryo induction showed that: (1) red radiation at10 mol m-2 s-1 significantly increased the density of total somatic embryos induced from carrot embryogenic calli; (2) lower and higher intensities of red radiation (1 to 5 mol m-2 s-1 and 20 mol m-2 s-1) did not significantly influence the density of induced total somatic embryos; and, (3) increasingthe intensity of blue radiation (up to 20 mol m-2 s-1) appeared to have reduced the density ofinduced total somatic embryos. In regard to somatic embryo development, the results showed that:(1) red radiation (up to 20 mol m-2 s-1) had virtually no effect on the development of the carrotsomatic embryos; and, (2) blue radiation (10 or 20 mol m-2 s-1) exerted positive effects on thedevelopment of the carrot somatic embryos, especially in the globular and heart-shaped stages.