Taxonomy and Grafting of Ornamental Cacti: A Review

Nowadays, cacti and succulents are widely utilized in landscaping. These plants suit very effectively for both indoor and outdoor decorations. The family Cactaceae comprises of 130 genera with 2000 species and this is primarily divided into three tribes namely: Pereskieae, Opuntieae and Cereeae. Cactus flowers are very attractive and are diverse in size, number, form and color. The nocturnal flowers are always white, with light-yellow or red tones, whereas diurnal flowers are white, purple, yellow-orange, red or green. Basically, an areole is a transformed axillary bud situated over a tubercle with spines and often with hairs and trichomes. Due to their low maintenance requirements and their ability to withstand harsh environments, cacti are extremely popular as ornamental plants across the planet. Cacti can be propagated by seeds, cuttings, offsets and grafts. Grafted cacti are now regarded as one of the most admired ornamental indoor plants worldwide. In cacti, grafting has become a commercial method of propagation to accelerate and hasten the growth rate of slow growing species, to ensure the survival of the plants with poor root system, to ensure the survival of genetic aberration of variegated and bright coloured cacti (red and yellow caps) that lack chlorophyll, to accelerate the growth of plants for commercial use, in order to keep cristate and monstrose forms look attractive. Successful grafts have been obtained when the species like Trichocereus spachianus, Trichocereus macrogonus, Trichocereus pachanoi, Hylocereus trigonus, Hylocereus undatus, Selenicereus grandiflorus, Opuntia bergeriana, Opuntia ficus-indica are grafted onto Nopalea spp. The exogenous application of IBA has a positive effect on the vegetative growth of grafted plants using (Gymnocalycium mihanovichii scion grafted onto Trichocereus spachianus rootstock.