Abstract
Effects of temperature, shade, and nitrogen application on the growth and contents of bioactive compounds in Plantago lanceolata L. were investigated by using two cultivars in a controlled environment. The cultivars that were grown at 15°C/10°C day/night temperatures were higher in top dry-matter weight, top dry-matter content, and the contents of acteoside, the phenylehtanoid glycosides, compared to those that were grown at 20°C/18°C temperatures. On the other hand, the contents of catalpol and aucubin, the iridoid glucosides, were higher in the plants grown at 20°C/18°C temperatures. It is assumed that the response of the accumulation of the compounds to temperature is different between phenylehtanoid and iridoid glucosides. Plants grown under shading treatment were lower in number of leaves per plant, top dry matter weights, and top dry matter contents, though they were higher in plant height. The contents of aucubin and acteoside were extremely lower in plants grown in the shade. It is apparent that shade represses the growth and accumulation of aucubin and acteoside in the cultivars of Plantago lanceolata L. Nitrogen application enhances the growth of the cultivars, especially the top fresh weight; on the other hand, it significantly diminished the top dry-matter content. The contents of aucubin and acteoside were apparently lower in the plants treated with nitrogen than in those that did not receive it.
