Agricultural and Food Engineering Department, Indian Institute of Technology Kharagpur, Kharagpur 721302, India.
Agricultural and Food Engineering Department, Indian Institute of Technology Kharagpur, Kharagpur 721302, India.
J Photochem Photobiol B. 2017 Sep;174:162-172. doi: 10.1016/j.jphotobiol.2017.07.029. Epub 2017 Jul 29.
The present study demonstrates the influence of LED irradiance of various wavelengths on shoot regeneration, biomass accumulation, photosynthetic pigment contents, and antioxidant potentials of Swertia chirata - a critically endangered medicinal plant. Mixed treatment of blue (BL) and red LEDs (RL) in equal proportion (1:1) significantly improved the shoot regeneration response. A machine vision system was developed to assess the shoot regeneration potential under different lighting treatments. Regenerated shoots exposed under BL:RL (1:1) exhibited higher biomass accumulation and canopy development compared to other lighting treatments. Improved canopy growth was evident from the increase in the area, major axis, minor axis, convex area, equivalent diameter and perimeter of regenerated shoot clusters. A higher correlation of dry weight (DW) was noted with the image feature, weighted density (WD) than the fresh weight (FW) in all the LED treated cultures. The significant correlation between DW and WD implies that the image feature WD can be adopted as a non-invasive approach for measuring biomass accumulation as well as detecting hyperhydricity. The developed machine vision approach provides a new direction in the evaluation of shoot organogenesis that displayed features including both shoot multiplication and canopy development. Chlorophyll and carotenoid contents of the regenerated shoots were found to be higher under BL:RL (1:1) than the other treatments. Supplementation of RL led to a reduction in the pigment contents. Spectral quality of lights also significantly influenced the accumulation of total phenolics, flavonoids and flavonols. Cultures exposed under BL exhibited the maximum accumulation of polyphenols. A similar effect of spectral quality was observed with the antioxidant capacity and reducing power potential of leaf extract. The findings demonstrate the ability of LEDs in inducing shoot regeneration as well as accumulation of phenolic antioxidants and suggest that the proportion of blue and red LEDs is an important factor in achieving the optimum response.
本研究表明，不同波长的 LED 辐照度对印度獐牙菜（一种极危药用植物）的芽再生、生物量积累、光合色素含量和抗氧化能力的影响。蓝（BL）和红（RL）LED 以相等比例（1:1）混合处理可显著提高芽再生反应。开发了一种机器视觉系统来评估不同光照处理下的芽再生潜力。在 BL:RL（1:1）下暴露的再生芽表现出比其他光照处理更高的生物量积累和冠层发育。从再生芽簇的面积、长轴、短轴、凸面积、等效直径和周长的增加可以明显看出冠层生长的改善。在所有 LED 处理的培养物中，与鲜重（FW）相比，干重（DW）与图像特征加权密度（WD）的相关性更高。DW 与 WD 之间的显著相关性表明，图像特征 WD 可以作为一种非侵入性方法来测量生物量积累以及检测过度水合。所开发的机器视觉方法为芽器官发生的评估提供了一个新的方向，该方法显示了包括芽增殖和冠层发育在内的特征。再生芽中的叶绿素和类胡萝卜素含量在 BL:RL（1:1）下高于其他处理。RL 的补充导致色素含量降低。光的光谱质量也显著影响总酚、类黄酮和类黄酮醇的积累。暴露在 BL 下的培养物表现出多酚的最大积累。在抗氧化能力和叶片提取物的还原能力方面也观察到了类似的光谱质量效应。研究结果表明，LED 能够诱导芽再生以及酚类抗氧化剂的积累，并表明蓝、红 LED 的比例是实现最佳响应的一个重要因素。
