Potential Use of Colored LED Lights to Increase the Production of Bioactive Metabolites Hedyotis corymbosa (L.) Lam

Hedyotis corymbosa (L.) Lam is a wild herb that is used in traditional Indian, Chinese, and African medicine. Light-emitting diode (LED) technology is paving the way to enhance crop production and inducing targeted photomorphogenic, biochemical, or physiological responses in plants. This study examines the efficiency of H. corymbosa (L.) Lam production under blue 450 nm and red 660 nm LED lights for overall plant growth, photosynthetic characteristics, and the contents of metabolite compounds. Our research showed that blue LED lights provided a positive effect on enhancing plant growth and overall biomass. In addition, blue LED lights are more effective in controlling the production of sucrose, starch, total phenolic compounds, and total flavonoid compared to red LED lights. However, blue and red LED lights played essential but different roles in photosynthetic characteristics. Our results showed the potential of colored LED light applications in improving farming methods and increasing metabolite production in herbs. LED lights are safer alternatives than genetically modified organisms or genome editing.

Effects of Potassium Silicate Fertilizer on Photosynthetic Characteristics and Yield in Winter Wheat (Triticum Aestivum L.)

Effects of different dosages of potassium silicate fertilizer on photosynthetic characteristics and yield of winter wheat under field conditions were studied. Four different dosages: 0, 45, 90 and 135kg/ha were applied. Results showed that the chlorophyll content, net photosynthetic rate of wheat flag leaf firstly increased and then decreased with the increase of levels of potassium silicate fertilizer. By the change of SPAD values after flowering, when the application of potassium silicate fertilizer was 90 kg/ha, the existence time of chlorophyll in flag leaf was significantly long, and the net photosynthetic rate was significantly increased. The 1000-grain weight of winter wheat significantly increased and the yield the highest. Overall, when the applied amount of potassium silicate fertilizer was 90 kg/ha, the performances of winter wheat were best. Bangladesh J. Bot. 50(4): 1127-1132, 2021 (December)

Effects of Drought Stress During Critical Periods on Photosynthesis Characteristics and Production Performance of Naked Oat (Avena Nuda. L)

Revealing the effects of drought stress during the critical period on the photosynthetic characteristics and production performance of naked oats could provide theoretical basis for optimizing the water managements and selecting the drought resistance cultivars. In this study, a potted experiment consisting of four water levels was conducted, to investigate the response of photosynthesis, chlorophyll fluorescence, biomass, yield and yield components of to drought stress during 12-15 days before heading at a typical site in Zhangjiakou. Results showed that the initial chlorophyll fluorescence rate (Fo) increased by 9.03-50.92% under drought stress, while the maximum fluorescence rate (Fm) and photochemical efficiency (Fv/Fm) decreased by 8.49-19.73% and 10.37-24.12%. Moreover drought stress decreased the photosynthetic rate (Pn), transpiration rate (Tr), stomatal conductance (Gs). The CO2 concentration (Ci) decreased under light drought stress, while increased under moderate and severe drought stress. Drought stress during critical periods also had significant impacts on oat yield and yield components. Oat yields decreased by 9.5-12.7%, 16.8-27.0% and 44.1-47.7% under light, moderate and sever drought stress, respectively. The yield components such as grains per spike, 1000-grain weight were decreased by 1.7-12.5%, 8.3-24.3%, 32.7-34.2% and 5.7-8.6%, 12.7-14.5%, 16.8-19.1% under light, moderate and severe drought stress, respectively. But the Spike numbers were not signifigantly different between different treatments. Our study explored the impacts of drought stress on the photosynthetic characteristics and production performance of naked oats, which had significance for enhancing the production efficiency for oat under drought stress.