Horticultural crops have been domesticated and further bred to satisfy human’s special dietary, medicinal, or esthetic needs. Their breeding, an interdisciplinary science, is moving toward a new horizon. Improvement of the unique qualities of horticultural crops has always been a major objective in breeding of these crops. In spite of the vast diversity of horticultural crops, most of the breeding goals are the same, for example, increasing 380productivity, concentrations of secondary metabolites, plant tolerance to pest, shelf-life, and altering the plant architecture of fruit trees and ornamentals. Recent advancements in the field of biotechnology have created a new domain to complement the methods of horticulture crop breeding.