Plastomes Reveal How Eggplants Became Asian

The history of eggplant has been obscure for a long time. Historical documents and genetic data show that eggplant was first domesticated in Asia, but most of its wild relatives are from Africa. Researchers from the Natural History Museums of London (NHM) and Finland (University of Helsinki) have now described the origin of the eggplant and its direct relatives.

The researchers sequenced the plastomes of eggplant and of 22 species directly related to the eggplant. The eggplant is a member of the genus Solanum within the nightshade family (Solanaceae). Solanum also accounts for two other globally important food crops, tomato and potato. But in contrast to these New World crops, the eggplant hails from Asia, where it was first domesticated somewhere in the region of China and India. Taxonomists only recently answered the question why many wild relatives of the cultivated eggplant are found in the savannahs of Africa.

The team found that the group containing the relatives of eggplant originated in northeastern Africa some two million years ago. Plants then dispersed both eastwards to tropical Asia and southwards to southern and western Africa. In tropical Asia, the dispersal event gave rise to a species that scientists call Solanum insanum, which is where populations of domesticated eggplant came from. What really startled the researchers was the fact that the dispersion of the group to Asia seemed to result from a single dispersal event from northern Africa to tropical Asia rather than a linear step-wise expansion from Africa to Asia.

For more details, read the press release from the University of Helsinki.