This study aimed to clarify the effect of the photosynthetic photon flux density (PPFD) ratio of red light (R) on that of blue light (B) radiated from an light emitting diode (LED) source on the growth and asperuloside biosynthesis of Hedyotis diffusa. Five experimental treatments with different ratios were established in a growth chamber as follows: R0B100, R25B75, R50B50, R75B25 and R100B0. For each ratio, two levels of PPFD were used: 100 and 150 μmol m^-2 s^-1. The results revealed that, under the same PPFD, the epigeous dry weight increased with the red-light percentage under simultaneous red and blue irradiation and decreased under red or blue monochromatic light. Under a chosen ratio, the epigeous dry weight increased with the light intensity. Asperuloside biosynthesis was suppressed under monochromatic light conditions and enhanced under simultaneous ones due to the enhanced supply of glucose, the main substrate of asperuloside biosynthesis, regardless of the ratio. Therefore, we concluded that the epigeous dry weight determined the asperuloside concentration.

　This study aimed to investigate the effects of 6-benzylaminopurine (BAP), a synthetic cytokinin, on N. cochenillifera daughter cladode development and growth. We injected different BAP concentrations (0, 1, 5, 25, and 50 ppm) into a mother N. cochenillifera cladode using a syringe. The number of daughter cladodes significantly increased under high BAP concentrations (25 and 50 ppm), although the total yield of daughter cladodes did not vary among treatments. Additionally, the fresh weight (FW) of each daughter cladode under 25 and 50 ppm BAP was lower than at other concentrations. Next, we tested different BAP application methods (injection, spraying, and lanolin paste). The number of daughter cladodes significantly increased under injection and spraying treatments compared with the control, and the yield of daughter cladodes was the highest under spraying. Finally, we combined thinning and BAP treatment to increase the size of a single stem. Under BAP treatment (injection) and thinning, the growth of daughter cladodes was significantly higher than the control, resulting in approximately 38% increase in FW. These results suggest that BAP is effective in promoting the growth and higher yield of N. cochenillifera.

　This study aimed to enhance the practicality and broaden the applicability of root phenotyping by reducing the cost of the hyperspectral imaging method proposed by Jin et al. (2025). To do so, we evaluated the feasibility of using a low-cost multispectral camera for the in situ monitoring of root growth and age in spinach (Spinacia oleracea L. cv. “Wase Kurone Horenso”) in a transparent hydroponics system. For this setup, plants were grown for 40 days, and root images were captured using the multispectral camera with 41 bands (i.e., 450–850 nm at 10 nm intervals). Root-background separation was subsequently performed based on reflectance intensity ratios, and a root age classification index for the multispectral camera was developed by analyzing the correlation between the reflectance intensity ratio and root age. Additionally, the index previously derived for hyperspectral camera (Jin et al., 2025) was applied for comparison. Relative to hyperspectral imaging, multispectral imaging demonstrated a comparable ability with respect to monitoring root growth and age distribution dynamics while significantly improving accessibility and robustness by reducing cost of the instrument, measurement time, and data processing. These findings highlight the potential of multispectral imaging as a practical alternative for nondestructive root monitoring in actual agricultural production.

　Plants utilize ionic and electrolytic activities to generate electrical signals for communication. This study explores realtime alternative current (AC) electrical measurements to monitor dynamic electrical properties in Marchantia polymorpha tissues in response to physical stimulation. Electrochemical impedance spectroscopy was used to monitor the transient tissue state changes, and the results reveal variations in electrical characteristics owing to ion movements. Electrochemical impedance spectroscopy parameters shows immediate responses, highlighting the potential for minimally invasive monitoring of transient phenomena in plant cellular dynamics. These findings enhance the understanding of AC impedance measurements in plant physiology and provide insights into the dynamic electrical responses of plant tissues.