Origin and evolution of cultivated cucurbits

Cucurbits (Cucurbitaceae) are among the most important plant families supplying humans with edible products and useful fibers. Plants of this family are very similar in above ground development, but they have high genetic diversity for fruit shape and other fruit characteristics, resulting in a variety of uses. The objective of this review was to discuss the origin and evolution of the most important cultivated cucurbits. Understanding the evolutionary history and domestication process increase the possibility for better exploiting the genetic diversity for cultivar development. The domestication selection in cucurbits was for shape, less bitter flesh, larger and fewer seeds, and larger fruit size, resulting in high genetic diversity within and among cultivated species. This variation can be associated with the wide range of uses that require different shape, size and a constant ratio between fruit length and fruit diameter. The discussion of the breeding history indicates how artificial selection could speed up changes in fruit characteristics to attend specific uses and increase adaptation to a variety of environmental conditions in which cucurbits are growing worldwide. Although interspecific hybridization has been employed in cucurbit breeding more than in any other family, there is still a high potential for increasing its application for germplasm and cultivar development.