Photomorphogenesis of wheat sprouts with LED irradiation of different intensities

Abstract

Definition of the growth and development characteristics of plants in varied light conditions is a key factor for the creation of highly efficient light facilities for plant cultivation. Experimental research was conducted using an LED irradiation facility with photosynthetic photon flux densities ranging from 0 to 261 μmol m−2 s−1 and a continuous spectrum with maxima at 445 and 600 nm. Under the maximum photosynthetic photon flux density (261 μmol m− 2 s−1) wheat germs demonstrated diminishing leaf surface with high values of specific leaf area, enhanced pubescence of ground tissues, increases in the number of stomata on the upper epidermis and palisade, and an increase in the thickness of the leaves as well as an increase in carotenoids but a decrease in the chlorophyll a+b/carotenoids relation. It was revealed that the optimum level of photosynthetic photon flux density for the referred spectrum was in the range from 82 to 100 µmol m−2 s−1, which may enable a reduction of irradiance under specific conditions during early development with no harm to the plants while minimizing energy consumption during cultivation.

UV and Visible Spectrum LED Lighting as Abiotic Elicitors of Bioactive Compounds in Sprouts, Microgreens, and Baby Leaves—A Comprehensive Review including Their Mode of Action

“…The photoperiod used under blue LED demonstrated the highest accumulation of antioxidant compounds, with significant differences compared to the growth under fluorescent or red lighting. Han et al [51] carried out a similar study in wheat sprouts, the results of which showed that 82 µmol m −2 s −1 blue LED was enough to achieve the maximum leaf parameters and enhance bioactive pigment content (carotenoids and chlorophylls). Similar results were also found by Park et al [52], who studied blue LED in contrast with red and white lighting (50 µmol m −2 s −1 ), results of which showed the highest accumulation of phenolics under blue LEDs and the longest development under red LEDs.…”