Chemical composition in wild Ethiopian Arabica coffee accessions

The exploration of accessions originating from Ethiopia is one option available to increase the genetic basis of new coffee cultivars. The aim of this study was to describe the chemical composition variability of Ethiopian coffee accessions maintained in Londrina and to evaluate the year effect on that. We observed no significant interaction between the years of cultivation and the amounts of caffeine, protein, lipids, chlorogenic acids, sucrose, cafestol and kahweol, thereby suggesting that evaluations of one year were reliable to describe this collection. All compounds showed variability, but the highest variability was found in cafestol and kahweol (32.81 and 34.45 %, respectively). Significant correlations among caffeine, chlorogenic acids and protein as well as between sucrose and lipids were observed. A significant negative correlation was found between kahweol and cafestol, and kahweol had positive and negative correlation with caffeine and chlorogenic acids, respectively. Hierarchical clustering analyses identified groups in the population, and the diversity found in one crop year was similar to that for 3 years. Greater diversity of composition was observed among the Western accessions compared to the ones from the East, but no clear separation was found between the accessions of these regions. These accessions are potential sources to increase the genetic diversity to obtain new coffee cultivars. (Résumé d'auteur