Dussert Stéphane, Laffargue Andréina, de Kochko Alexandre, Joët Thierry
IRD, UMR DIAPC, Montpellier, France.
Phytochemistry. 2008 Dec;69(17):2950-60. doi: 10.1016/j.phytochem.2008.09.021. Epub 2008 Nov 6.
The chemotaxonomic relationships between Coffea (subgenus Coffea) species have been poorly studied to date and the compounds tested so far - chlorogenic acids, diterpenoids and purine alkaloids - did not enable the establishment of phylogenetic relationships analogous to those revealed by chloroplast and nuclear DNA studies. In the present study, the relationships between African Coffea species were assessed on the basis of their seed lipid composition. Fatty acids and sterols were determined in 59 genotypes belonging to 17 distinct Coffea species/origins. Principal Component Analysis of fatty acid and sterol data enabled easy identification of the few species for which one or several compounds could serve as a quantitative signature. Hierarchical Clustering classified the Coffea species in seven groups with both fatty acids and sterols. However, while groupings based on seed fatty acid composition showed remarkable ecological and geographical coherence, no phylogeographic explanation was found for the clusters retrieved from sterol data. When compared with previous phylogenetic studies, the groups deduced from seed fatty acid composition were remarkably congruent with the clades inferred from nuclear and plastid DNA sequences.
迄今为止，对咖啡属（咖啡亚属）物种之间的化学分类关系研究甚少，目前所检测的化合物——绿原酸、二萜类化合物和嘌呤生物碱——无法建立类似于叶绿体和核DNA研究中所揭示的系统发育关系。在本研究中，基于非洲咖啡属物种的种子脂质组成评估了它们之间的关系。测定了属于17个不同咖啡物种/来源的59个基因型中的脂肪酸和甾醇。对脂肪酸和甾醇数据进行主成分分析，能够轻松识别出少数几种可以将一种或几种化合物用作定量特征的物种。层次聚类将咖啡属物种分为基于脂肪酸和甾醇的七组。然而，虽然基于种子脂肪酸组成的分组显示出显著的生态和地理一致性，但未找到从甾醇数据中检索到的聚类的系统地理学解释。与之前的系统发育研究相比，从种子脂肪酸组成推导的组与从核DNA和质体DNA序列推断的进化枝非常一致。
