Aloe L., is the largest genus in the Xanthorrhoeaceae, (sub-family Asphodeloideae), a family of succulent-leaved, petaloid monocots. Aloes exhibit remarkable morphological variability and range in size from dwarf species to trees reaching heights of up to 20 m. Aloes are well represented in Southern Africa and especially South Africa, where they form an important component of the local flora from taxonomic, ethnomedicinal, chemical/chemotaxonomic, ecotouristic and horticultural perspectives. They are cultivated in open fields in tropical and semitropical climates, in greenhouses in temperate climates, for ornamental, edible, medicinal and cosmetic purposes. The species A. vera (L.) Burm. f. [sin. A. barbadensis Mill., A. vulgaris Lamk.] and A. arborescens Mill. are the most widely cultivated around the world. Medicinal use of aloe leaves dates back thousands of years and today aloes are world-renowned as a source of natural products derived from the leaf exudate and mesophyll. Mainly, active substances have been ascribed to ß-polysaccharides (located in the inner leaf parenchyma) and phenolic compounds such anthrones, chromones and their glycosides. Among others, the therapeutic potential related to these compounds includes wound-healing, antioxidant, antimicrobial, immunostimulant and anticancer properties. The aim of this review is to provide an exhaustive collection of its bio-cultural values, health and therapeutic aspects and agronomic needs in order to improve the quantity and quality of the product. This knowledge will be of potential importance both to increase qualitative and quantitative traits of the production, as well as to protect biodiversity. In vivo multiplication occurs through adventitious shoots that are formed on the underground stem but their formation is limited and has a seasonal frequency which makes this technique very slow and expensive. In vitro culture is an alternative propagation method, which facilitates large scale production in limited time and space. This review provides information for A. vera and A. arborescens about their pedo-climatic needs, agronomic aspects, both outdoors and in greenhouses, with particular reference to location and accommodation, irrigation and fertilization, as well as leaf production.
Keywords: propagation, growing technique, anthrones, chromones, acemannan