Effect of Light Intensity and Temperature on the Growth and Functional Compounds in the Baby Leaf Vegetable Plant Peucedanum japonicum Thunb.

This study was carried out to determine the optimal light intensity and temperature for cultivation of Peucedanum japonicum Thunb., a new baby leaf vegetable, and to improve the functional compounds through short-term stress just before harvesting. Plants were cultivated in a controlled environment at a temperature of 25 ± 1°C and relative humidity of 60 ± 5% for 16 days. Plants 3-5 cm high with 1 st and 2 nd true leaves were grown with different light intensities or temperatures. Treatments were 50, 100, 250, or 500 μmol·m -2 ·s -1 PPFD and 18/14°C, 24/20°C and 30/26°C of day and night temperature. At the harvest time of the baby leaf vegetables, growth, chlorophyll content, and functional compounds were investigated. The optimum light intensity for growth of P. japonicum Thunb. was PPFD 250 for 12 days, and the best temperature was 24/20°C. Total phenolic content was higher under high light intensity and low temperature treatment. When the plants were treated for 3 days with temperature (18/14°C and 25/20°C) and light intensity (PPFD 200 and 500) before harvesting, there was no difference in growth, but total phenolic content was high in PPFD 200 or 500 under 18/14°C treatments. Free radical activity (DPPH) was significant for temperature and light treatment. The highest free radical activity was in PPFD 500 under 18/14°C treatments. Therefore, after cultivation at optimal light and temperature, low-temperature treatment for three days before harvesting was effective for enhancing the functional contents. Additional key words: chlorophyll, LED, phenolic contents, short-term stress, specific leaf area

[1]  Wenke Liu,et al.  Effects of light quality, light intensity, and photoperiod on growth and yield of cherry radish grown under red plus blue LEDs , 2018, Horticulture, Environment, and Biotechnology.

[2]  R. Suwa,et al.  Polyphenol Production in Peucedanum japonicum Thunb. varies with Soil Type and Growth Stage , 2018 .

[3]  U. Pérez-López,et al.  Concentration of phenolic compounds is increased in lettuce grown under high light intensity and elevated CO2. , 2018, Plant physiology and biochemistry : PPB.

[4]  K. Jeon.  Characteristics of Growth and Photosynthesis of Peucedanum japonicum by Shading and Leaf Mold Treatment in Forest Farming , 2016 .

[5]  M. Oh,et al.  Short-term low temperature increases phenolic antioxidant levels in kale , 2015, Horticulture, Environment, and Biotechnology.

[6]  Jun Gu Lee,et al.  Effect of Air Temperature on Growth and Phytochemical Content of Beet and Ssamchoo , 2015 .

[7]  Yonghua Zheng,et al.  Effect of light on quality and bioactive compounds in postharvest broccoli florets. , 2015, Food chemistry.

[8]  Simhee Han,et al.  Effects on Growth, Photosynthesis and Pigment Contents of Liriodendron tulipifera under Elevated Temperature and Drought , 2015 .

[9]  Min-Jeong Lee,et al.  Growth and phenolic compounds of Lactuca sativa L. grown in a closed-type plant production system with UV-A, -B, or -C lamp. , 2014, Journal of the science of food and agriculture.

[10]  Seung-Hun Cho,et al.  The Protective and Recovery Effects of Peucedanum Japonicum Thunberg for Vascular Dementia , 2013 .

[11]  Eun Ju Lee,et al.  Screening of Whitening and Anti-wrinkle Efficacy of Peucedani Japonici Radix , 2013 .

[12]  T. Toda,et al.  Peucedanum japonicum Thunb Inhibits High‐fat Diet Induced Obesity in Mice , 2011, Phytotherapy research : PTR.

[13]  C. Kubota,et al.  Effects of supplemental light quality on growth and phytochemicals of baby leaf lettuce , 2009 .

[14]  M. Oh,et al.  Environmental stresses induce health-promoting phytochemicals in lettuce. , 2009, Plant physiology and biochemistry : PPB.

[15]  Chunzhang Zhao,et al.  Growth and photosynthetic responses of two coniferous species to experimental warming and nitrogen fertilization , 2009 .

[16]  Alexander Ac,et al.  Differences in pigment composition, photosynthetic rates and chlorophyll fluorescence images of sun and shade leaves of four tree species. , 2007, Plant physiology and biochemistry : PPB.

[17]  M. Talón,et al.  Responses of citrus plants to ozone: leaf biochemistry, antioxidant mechanisms and lipid peroxidation. , 2006, Plant physiology and biochemistry : PPB.

[18]  Jeong-Han Kim,et al.  Effect of far-infrared radiation on the antioxidant activity of rice hulls. , 2003, Journal of agricultural and food chemistry.

[19]  R. Mcavoy,et al.  Supplemental light before harvest increases phenethyl isothiocyanate in watercress under 8-hour photoperiod , 1997 .

[20]  R. Dixon,et al.  Stress-Induced Phenylpropanoid Metabolism. , 1995, The Plant cell.

[21]  G. Mackinney,et al.  ABSORPTION OF LIGHT BY CHLOROPHYLL SOLUTIONS , 1941 .