Growth of Micropropagated Solanum tuberosum L. Plantlets under Artificial Solar Spectrum and Different Mono- and Polychromatic LED Lights

Abstract

In agriculture, LED light sources have increasingly replaced the standard luminescent lamps and have acquired an important role in plant micropropagation. We studied the effect of different light sources such as narrow-band LEDs (bright blue, blue, green, yellow, deep red, and red) and wide-band LEDs (cold white, white, warm white, full spectrum, and an artificial solar spectrum sun box constructed by us) on development of potato plantlets in vitro. White luminescent lamps were used as a control. The light intensity of 49 µmol · m−2 · s−1 was provided in all light treatments. We showed that the long-wave narrow-band light treatments were inapplicable for potato micropropagation, because plantlets were weak with small leaves, inhibited roots, and significantly elongated stems. Blue lights provided growth of shortened plantlets with large leaves, well-growing roots, and abundant green mass. The chlorophyll content was lower under blue and bright blue light and was at the same level in the remained treatments. Significant differences in the stomatal apparatus development were observed depending on the light source. These differences were not always reflected in the plantlet phenotype: e.g., plantlets under blue and bright blue lights showed no differences in any characteristics except stomatal density and size of stomatal guard cells. We found no significant effect of blue light portion in the white lights and full spectrum on plantlet growth. An artificial solar spectrum sun box was the most suitable for potato micropropagation, because it supported the development of plantlets with good fitness, uniform internodes length, abundant roots and green mass accumulation.

Keywords

• Solanum tuberosum
• LED
• Artificial solar light
• Growth
• Micropropagation