Citrus origin and domestication: an evolutionary paradigm for the genus citrus

The genius Citrus and related genera are widely distributed across the monsoon region from West Pakistan to north-central China and south through the East Indian Archipelago to New Guinea and Bismarck Archipelago, northeastern Australia, New Caledonia, Melanesia and the western Polynesian islands. Native habitats of these genera roughly extends throught this broad area, although the center of origin, timing, dispersal and domestication of citrus species across Southeast Asia remains unclear. The major hindrance to work out these unresolved ambiguities is intimately related to our poor understanding of the complex admixture genealogy of cultivated citrus as recently we revealed. Presumably, the historical association of humans with cultivated citrus that have been genetically fixed through grafting and apomixis, has led to foremost uncertainties on the genetic composition of citrus, a substantial gap precluding the elucidation of citrus ancestry. In this presentation, we combine genome sequence analysis and biogeographic evidence to characterize the genetic diversity and evolution of citrus. This information offers solid insights on the origin, dispersal and domestication of citrus, revealing a new evolutionary paradigm for the genus Citrus. (Texte integral)