Phenolic compounds are involved in plant response to environmental conditions and are highly present in leaves of Coffea arabica L., originally an understory shrub. To increase knowledge of C. arabica leaf phenolic compounds and their patterns in adaptation to light intensity, mature leaves of Ethiopian wild accessions, American pure lines and their relative F1 hybrids were sampled in full sun or under 50% shade field plots in Mexico and at two contrasting elevations in Nicaragua and Colombia. Twenty-one phenolic compounds were identified by LC-DAD-MS² and sixteen were quantified by HPLC-DAD. Four of them appeared to be involved in C. arabica response to light intensity. They were consistently more accumulated in full sun, presenting a stable ratio of leaf content in the sun vs. shade for all the studied genotypes: 1.6 for 5-CQA, F-dihex and mangiferin and 2.8 for rutin. Moreover, 5-CQA and mangiferin contents, in full sun and shade, allowed for differentiating the two genetic groups of Ethiopian wild accessions (higher contents) vs. cultivated American pure lines. They appear, therefore, to be potential biomarkers of adaptation of C. arabica to light intensity for breeding programs. We hypothesize that low 5-CQA and mangiferin leaf contents should be searched for adaptation to full-sun cropping systems and high contents used for agroforestry systems.

中文翻译：

---

5-CQA 和芒果苷，阿拉比卡咖啡适应全日照或遮荫条件的两叶生物标志物。


酚类化合物参与植物对环境条件的反应，并且大量存在于阿拉比卡咖啡（最初是一种林下灌木）的叶子中。为了增加对阿拉比卡咖啡叶酚类化合物及其适应光强度模式的了解，在墨西哥和墨西哥的全日照或 50% 遮荫田地中对埃塞俄比亚野生品种、美国纯系及其相关 F1 杂交种的成熟叶子进行了采样。尼加拉瓜和哥伦比亚的两个截然不同的海拔。通过 LC-DAD-MS ²鉴定了 21 种酚类化合物，通过 HPLC-DAD 定量了 16 种酚类化合物。其中四个似乎参与了阿拉比卡咖啡豆对光强度的反应。它们在充足的阳光下持续积累得更多，对于所有研究的基因型来说，在阳光下与阴凉处的叶子含量呈现出稳定的比例：5-CQA、F-dihex 和芒果苷为 1.6，芦丁为 2.8。此外，在充足的阳光和阴影下，5-CQA 和芒果苷含量可以区分埃塞俄比亚野生种质（含量较高）与栽培的美国纯系的两个遗传群体。因此，它们似乎是阿拉比卡咖啡豆适应育种计划光强度的潜在生物标志物。我们假设应寻找低 5-CQA 和芒果苷叶含量以适应全日照种植系统，并寻找高含量用于农林业系统。