The Study of Light Environments for in vitro Growth of Limonium and Gentiana Using LED Light Control System

The development of seedlings production technology in recent years; tissue culture has been widely applied in seedlings industry. In the control of light environment of tissue culture, Light-Emitting Diodes (LEDs) are new culture light. In comparision between fluorescent lamps and LEDs, LEDs have lower heat generation, specified wavelength and lower power consumption in research and seedlings industry. In the research, LED light environment control system (LECS) (Chen, 2005) and LED Light Control System developed in this study were designed for different light environment, and they were used to in vitro growth of Limonium, and Gentiana. Taguchi Method - signal of noise ratio combine with Principal Component Analysis (PCA), a set of property indexs were transformed into a comprehensive index that can reflect quality and variability. To probe into the optimal light environment of Limonium, and Gentiana by using main effect analysis and Response Surface Method (RSM). he analysis of ex vitro quality of Limonium, there are two experiments (light quality, light intensity; light quality, light intensity, photoperiod). Among of them, the secondary experiment can do analysis of light quality and light integral. The leaf morphological parameters, leaf chlorophyll fluorescence and plant morphological parmeters of the Limonium were effected significantly after different light environment of culture. The optimal light environment condition of comprehensive ex vitro index (plant height is high, chlorophyll contents (SPAD-502 reading, CMR) is high, leaf area is big, dry weight is heavy), light quality: 80 % red +20 % blue ~ 70 % red +30 % blue (R/B ratio = 4~R/B ratio = 7/3), light intensity:120 μmol m-2 s-1, photoperiod:16 hr/day and light integral:6.62 mol m-2. he analysis of ex vitro quality of Gentiana and the analysis of ex vitro quality of Limonium are the same, and it also did specific light quality experiment and supplemental experiment (light quality, light intensity, photoperiod). The leaf morphological parameters, leaf chlorophyll fluorescence, and plant morphological parmeters of the Gentiana were effected significantly after different light environment of culture. The optimal light environment condition of comprehensive ex vitro index one (chlorophyll contents (SPAD-502 reading, CMR) is high, height of internode is short, leaf area is big, dry weight is heavy), light quality: 30 % red +70 % blue ~ 80 % red +20 % blue (R/B ratio = 3/7 ~ R/B ratio = 1/4), light intensity: 120 μmol m-2 s-1, photoperiod: 16 hr/day and light integral: 6.69 mol m-2. In supplementa1 experiment, the optimal light environment condition of comprehensive ex vitro index two (chlorophyll contents (SPAD-502 reading, CMR) is high, sturdiness quotient is small, leaf area is big, dry weight is heavy), light quality: 35 % red +65 % blue (R/B ratio = 0.55), light intensity: 122.5 μmol m-2 s-1, photoperiod: 16 hr/day.The optimal light environment condition of comprehensive ex vitro index two is close to comprehensive ex vitro index one. The result show that: height of internode or sturdiness quotient is appropriate to analysis of the optimal light environment condition of comprehensive ex vitro index of Gentiana.he analysis of medicinal properties of Gentiana and the analysis of ex vitro quality of Gentiana have the same experimental design. The overall medicinal contents (mg/plant) of Gentiopicroside and Swertiamarin were effected significantly after different light environment of culture. The optimal light environment condition of comprehensive medicinal index one (overall medicinal contents (mg/plant) of Gentiopicroside and Swertiamarin are high), light quality: 50 % red + 50 % blue ~ 80 % red + 20 % blue (R/B ratio = 1 ~ R/B ratio = 1/4), light intensity: 120 μmol m-2 s-1, photoperiod: 20 hr/day and light integral: 8.64 mol m-2. The optimal light environment condition of comprehensive medicinal index two (the medicine contents (mg/mg) of Gentiopicroside and Swertiamarin are high), light quality: 20 % red + 80 % blue (R/B ratio = 4), light intensity: 120 μmol m-2 s-1, photoperiod: 20 hr/day and light integral: 8.64 mol m-2. The optimal light environment condition of overall medicinal contents (mg/plant) of Gentiopicroside, light quality: 50 % red + 50 % blue ~ 80 % red + 20 % blue (R/B ratio = 1 ~ R/B ratio = 1/4), light intensity: 120 μmol m-2 s-1, photoperiod: 20 hr/day and light integral: 8.64 mol m-2. The optimal light environment condition of overall medicinal contents (mg/plant) of Swertiamarin, light quality: 50 % red + 50 % blue (R/B ratio = 1), light intensity: 120 μmol m-2 s-1, photoperiod: 20 hr/day and light integral: 7.36 mol m-2.s a conclusion, the study used Light-Emitting Diodes (LEDs), and it has successfully analyzed the optimal light environment condition (light quality, light intensity, photoperiod, light integral) of ex vitro quality of Limonium and Gentiana and medicinal properties of Gentiana by using experimental design and optimal analysis. With these research results, LEDs and the optimal light environment condition could be used to the light environment of tissue culture in the future. It is useful for ex vitro quality of Limonium and Gentiana and medicinal properties of Gentiana.