LED lighting affects maturation, conversion and metabolic profile of somatic embryos derived from Kelussia odoratissima Mozaff

The present study investigated potential application of somatic embryogenesis (SE) for conservation of Kelussia odoratissima Mozaff. As the efficiency of SE greatly varies depending on the culture conditions including light, effects of five light spectrums including a fluorescent light and four types of light - emitting diode (LED) (red, blue, 3red-1blue, and 3blue:1red) for an exposure time of a month on the maturation of K. odoratissima were studied. To better understand the effect of light treatment on conversion of K. odoratissima cultures, two months after treatment, fresh and dry weight and metabolite contents were evaluated. Samples of the same age in-situ plant and air-dry plant were also considered for relative comparison. Study of developmental stage of K. odoratissima under in vitro conditions revealed that a combination of 3red:1blue LED provided the highest number of cotyledonary (mature) embryos per callus. Interestingly, 3red:1blue LED could significantly improve synchronization of somatic embryos. Hence, this light treatment was identified as the best treatment for the maturation of somatic embryos in K. odoratissima. In conversion stage, the highest fresh and dried weights were recorded for tissue culture plantlets grown under 3blue:1red and blue LED treatment. Phthalide content of fresh in-situ plant was significantly greater than other treatments. Interestingly, the phthalide content was significantly higher in leaves of tissue culture plantlets compared to air-dry in situ plants, which suggests tissue culture as an alternative technique for the production of bioactive compounds in K. odoratissima.