Uncovering Coffee Beans' Genes

One of the scientists' goals is to ensure that coffee's genetic diversity, or gene pool, is preserved for the future. That's because as-yet-unknown genes in today's popular commercial coffee varieties or in their wild, uncultivated relatives might hold the key to delicious new coffees for tomorrow.

The researchers examined coffee's genetic material, or DNA, to look for similarities and differences. Any dissimilarities among the species could be important. They could reveal interesting genes, such as ones that make some plants hardier or more disease resistant, or make their beans more flavorful.

The researchers analyzed Coffea arabica and C. canephora, the two most widely grown coffees in the world, and C. liberica, grown commercially in the Philippines as well as in parts of Africa. C. arabica was about 50 percent different from C. canephora and C. liberica. These differences may explain why these species vary in their resistance to pests, for example, or thrive at disparate elevations. Of the five C. arabica varieties studied, Catimor and Mokka Hybrid differed the most from each other--information that could eventually result in a better cup of coffee.

These studies are the most comprehensive genetic analyses to date of cultivated C. arabica coffees and the first to use a sophisticated laboratory technique called AFLP (amplified fragment length polymorphism). The scientists' findings were reported earlier in the journal Theoretical and Applied Genetics.