Abstract

Ipecacuanha [Carapichea ipecacuanha) (Brot) L. Andersson] has a high commercial value due to the presence of emetine and cephalin in its roots, which can be enhanced by different levels of light intensity. This study aimed to study the physiological response of ipecacuanha plants under different shading levels (50, 70, and 90%) in all seasons. Plants were cultivated in a greenhouse with sombrite® (shading) for 395 days, in beds containing sandy soil, after which we evaluated chlorophyll (Chl) a fluorescence, photosynthetic pigments and emetine and cephalin. Chl a fluorescence was higher in plants under 50% shading in all seasons while plants under 90% shading showed increases in Chl a fluorescence in the summer. The changes in Chl a fluorescence under 50% shading reveal difficulties in adaptation to high light levels, since high light intensity causes disorders in the dynamic dissipation of photosynthetic energy, and a decrease in photosynthetic pigments. The highest content of cephalin was recorded in winter under 70% shading, whereas for emetine it was recorded in spring, under 90% shading. Autumn (70% shading) was the only season in which the amount of both emetine and cephalin was similar. Therefore, both the season and the shading level affect ipecacuanha metabolism.

摘要

Ipecacuanha [ Carapichea ipecacuanha ) (Brot) L. Andersson] 因其根部存在吐根碱和脑磷脂而具有很高的商业价值，可通过不同程度的光照强度增强。本研究旨在研究不同遮荫水平（50%、70% 和 90%）下吐根植物在所有季节的生理反应。植物在带有 sombrite®（遮荫）的温室中培养 395 天，在含有沙质土壤的床中，之后我们评估了叶绿素 (Chl) a荧光、光合色素以及吐母碱和脑磷脂。在所有季节，50% 阴影下的植物中叶绿素a荧光较高，而在夏季，90% 阴影下的植物显示叶绿素a荧光增加。Chl的变化50% 阴影下的荧光表明难以适应高光水平，因为高光强度会导致光合能量动态耗散的紊乱，以及光合色素的减少。在 70% 的遮荫下，冬季记录了最高的脑磷脂含量，而在春季，在 90% 的遮荫下记录了依米汀的最高含量。秋季（70% 的阴影）是唯一一个依米丁和脑啡肽含量相似的季节。因此，季节和遮荫程度都会影响吐根叶的新陈代谢。