GENETIC ALTERATIONS ASSOCIATED WITH THE ORIGINS OF FRUIT CULTURE

The origins of modern fruit culture occurred in the Fertile Crescent in the late Neolithic and Bronze Age (6000 to 3000 BCE) with date palm, olive, grape, almond, fig and pomegranate.
Central Asian temperate fruits including pome fruits (apple, pear, quince and medlar) and stone fruits (almond, apricot, cherry, peach, and plum) were fully domesticated by antiquity.
Citrus fruits were domesticated early in China but reached the West in waves starting with citron.
A number of popular fruits (strawberry, blueberry, cranberry, and kiwifruit) were only domesticated in the 18^th, 19^th, and 20^th centuries while many fruits, although extensively collected and marketed, remain to be domesticated (lingonberry, various cacti and durian). Domestication of fruit crops resulted from vegetative propagation of elite natural variants with further improvement from selection of natural recombinants produced by natural intercrosses involving improved types.
Cultural practices often unique to each crop, such as irrigation, pollination control, grafting, rootstocks, pruning and training, storage, and processing, were developed to increase productivity, improve quality and extend use.
Genetic variants that were selected included breakdown of dioecy, improvement of fruit size, increased sugars or oil, ease of vegetative propagation, seedlessness, parthenocarpy, loss of thorns, breakdown of self-incompatibility, pest resistance, and increased productivity, quality, storage and shelf life.
Factors contributing to improvement include mutation, interspecific recombination, polyploidization through unreduced gametes, and selection involving generations of sexual recombination.
However, not until the beginning of the 19^th century was selection purposely imposed through cycles of seed propagation (Jean Baptiste Van Mons, 1765-1842, in pear) nor hybridization pursued (Thomas Andrew Knight, 1759-1838, in apple and pear, redcurrant and strawberry, and cherry, nectarine, and plum). Current progress has been achieved through intensification of the same forces that have occurred naturally with emphasis on increased adaptability through hardiness, chill requirements, photoperiod insensitivity and resistance to biotic stress.
Because many of our fruits are essentially little changed from wild types, continued progress should be possible.
Molecular techniques hold out the promise of increasing the efficiency of selection through molecular markers and insertion of individual genes through transgene technology.

XI Eucarpia Symposium on Fruit Breeding and Genetics

J. Janick

domestication, vegetative propagation, grafting, fruit breeding

https://doi.org/10.17660/ActaHortic.2004.663.123