Prunus

Abstract

Prunus (Rosaceae), a genus of some 200 species of trees and shrubs widely distributed in both the Old and New Worlds, includes many of the most economically important fruit crops of temperate regions as well as species cultivated as ornamentals and others used as timber trees and for medicinal purposes. Best known from the temperate zone of the northern Hemisphere, the genus is also well-represented in tropical regions in Asia and the Americas, though the species from the latter areas have received little attention from researchers until now. Molecular phylogenetic studies to date have failed to provide strong resolution of relationships across the genus, but with increasing sampling of both taxa and informative loci, a consistent picture is beginning to emerge, indicating a need for a new phylogenetically based infrageneric classification. The abundance and diversity of wild species closely related to the numerous important crop plants in this group have resulted in significant use of the former as rootstocks, in classical and modern breeding efforts, and in evolutionary and genetic studies of the wild species and of economically important and biologically interesting traits such as gametophytic self-incompatibility. The existence of genetic tools developed for the cultivated species has, in turn, facilitated the study of population genetics, evolution, and ecology of the wild species. A range of conservation statuses exists in Prunus, with species varying from those that are rare and endangered to those that are widely distributed and common, including some that have become invasive in areas to which they are not native. Germplasm collections exist throughout the world, but the tropical species, which include some of the least well-known and the most endangered taxa, are not well represented.