Pitahayas: Introduction, agrotechniques, and breeding

Vine cacti of the genera Hylocereus and Selenicereus, native to the tropical regions of northern South America, Central America and Mexico, are an epiphytic group of plants bearing edible and exotic fruits. The flowers are nocturnal and remain open only for few hours. The fruits, known in Latin America as pitahaya, are sweet, juicy, and have black small crispy seeds with either a spineless (Hylocereus species) or a spiny (Selenicereus) peel. Due to the fact that pitahaya species are currently being cultivated in many countries including Mexico, Colombia, Ecuador, United States, Israel, Thailand, Malaysia, Indonesia, Japan, China, and Australia, interest in these crop species is increasing. Despite their great economic potential, vine cacti have not received much attention from researchers and little was known about these species. The first steps in introducing and domesticating these species included the development of appropriate agricultural techniques for profitable cultivation. Early studies revealed that these species are sensitive to high irradiation, extreme temperatures and saline water irrigation. Due to the self-incompatibility system of many cultivars, hand cross pollination is necessary. To ensure a continuous supply of compatible pollen for obtaining high yields, a pollen cryopreservation technique was developed. Successful reciprocal crosses were performed, and improved hybrids were obtained. Fruit development, ripening periods, and optimum harvesting time were studied for the different clones. Further intensive research and development will contribute greatly to the domestication and commercial production of these fruit crops in arid zones, where they are not yet cultivated. In addition, focused marketing efforts could lead to an even greater consumer acceptance and, hence, expanded markets. This review addresses the key findings on introduction, use, nutritional value, genetic resources, production, and on-going research programs.