Cactus is a drought-resistant plant that has edible, medicinal and fodder values. Opuntia cactus is cultivated in arid and semi-arid regions of the world to produce fresh fruits, bioenergy, cosmetics, medicine and fodder. On the other hand, growth regulators play a key and essential role in the primary metabolism of plants, and the growth and development of plants, especially the effective substances of medicinal plants, can depend on plant growth regulators. Gibberellic acid can play an essential role in increasing the content and performance of the active substance of medicinal plants and increase the biosynthesis of the products of secondary metabolic pathways.
This research was conducted to investigate the effect of gibberellic acid on the growth, phytochemical and fodder quality of four species of Opuntia cactus. The factorial experiment in the form of a completely randomized design with three replications was designed and carried out in the research farm of the Faculty of Agriculture and Natural Resources of the Persian Gulf University. Factors included four species of Opuntia cactus (Stricta, Ficus indica, Engelmannii and Ellisiana) and three concentrations of gibberellic acid hormone in three concentrations (0, 100 and 200 ppm). In this study, the morphological traits including the length, width and diameter of the pad, the length of the fruit and spine, the number of pads and flower buds and the amount of gel, as well as after harvesting antioxidant content, total phenol, total flavonoid and forage quality were investigated.
The results of analysis of variance indicated that the type of cactus species and gibberellic acid concentration were significant for all investigated traits. Also, the use of gibberellic acid regulatory hormone caused an increase in all investigated traits, including growth traits, secondary metabolites, and forage quality indicators, and for most traits, it reached its maximum value at a concentration of 200 ppm. In the investigation