All arabica coffee is genetically similar: how can beans taste so different?
Flavour variations are mainly the result of changes at the chromosome level, sequencing effort finds.
The differences in the flavour notes and other characteristics of coffee varieties from around the world are not down to variations in individual genes, a study has found. Rather, they seem to be mainly the result of wholesale swapping, deletion and rearrangement of chromosomes.
The most complete sequencing yet of the genome of Coffea arabica has revealed that the ‘letters’ in the DNA strands differ only slightly between varieties. Despite this, there is substantial variation in the physical characteristics of the arabica coffee plant, including different flavour profiles in the beans and variations in disease resistance.
The study found evidence of significant chromosomal rearrangements, especially in a varietal of C. arabica called Bourbon. There were deletions, in which fragments of chromosomes were missing — in some cases large chunks — and even instances in which entire chromosomes were absent. “In some varieties, you had either only three [chromosome] copies — let’s say two canephora, one eugenioides — in another one you had five copies — two eugenioides, three canephora,” Morgante says.
https://doi.org/10.1038/d41586-024-00165-x
References
Scalabrin, S. et al. Nature Commun. https://doi.org/10.1038/s41467-023-44449-8 (2024).