An Introduction to Almond Species and Their Origins

Almond species, in addition to their historical importance as food crops, are becoming increasingly utilized in reforestation, ecological restoration, and urban landscaping. Their historical distribution extends across Central Asia, displaying adaptation to a wide range of ecological niches and resulting in an exceptionally high genetic diversity that drives the continuing evolution of multiple ecotypes, species, subspecies, and strains. An understanding of the genetic and evolutionary relationships among different species is important for estimating both horticultural and breeding values. Almond improvement is currently limited by relatively narrow breeding germplasm, with genetic improvement programs increasingly turning to wild relatives as a source for improved climate resilience, kernel quality and productivity, and resistance to diseases and pests. Exotic almond germplasm is also enabling the sometimes-dramatic transformation of traditional cropping systems, as with the transfer of self-fruitfulness from related species to normally self-sterile cultivated almonds.