The Gymnocalycium genus includes numerous highly valued species in the ornamental plant market and their propagation is usually carried out using traditional methods. However, there is a lack of information regarding the efficiency of micropropagation through in vitro tissue culture techniques on these species. So, with the objective of establishing an efficient micropropagation protocol that allows for optimizing the plant obtaining processes, the morphogenic potential of Gymnocalycium cv. Fancy has been studied in this work. For this purpose, plants of two different sizes (medium and large) were used as the starting material, from which three types of explants were obtained (apex, central discs and bases). The effect of three plant growth regulators (6-Benzylaminopurine, BAP; Kinetin, KIN; and Thidiazuron, TDZ) at three different concentrations each were studied, and the number of generated shoots, the frequency of appearance of callogenesis and rhizogenesis by explant and condition were assessed. An efficient protocol based on the use of KIN at 4 µM and central discs as a starting explant was developed. Moreover, the obtained sprouts rooted successfully (especially using BAP at 2 µM), and their subsequent acclimatization was very effective. Furthermore, emergence of a new morphotype is presented, that has not previously been described.

This study aims to establish efficient in vitro propagation protocols for Gymnocalycium cv. Fancy, an ornamental cactus with variegated variants, by evaluating the effects of cytokinin type and explant source on the organogenic response. Plants with different degrees of variegation (0–100%) were classified by size to obtain different explant types (apices, central discs, epicotyls, and hypocotyls). The effects of 6-Benzylaminopurine (BAP, 8 µM), Kinetin (KIN, 4 µM), and Thidiazuron (TDZ, 1 µM) were assessed on shoot production, callus formation, and rhizogenesis. Additionally, we studied the relationship between initial plant variegation and the productivity of the variegated shoots. The best shoot production results were obtained for central discs treated with 1 µM TDZ. Furthermore, a correlation was observed between the activated areole type (green, mixed, or fully colored) and shoot color percentage, enabling precise explant selection. The appearance of differently colored shoots confirms the potential for selecting new lines from this cultivar too. These findings hold significant potential not only for the breeding and propagation of ornamental cacti but also for the cultivation of other edible cacti and their relatives.

Gymnocalycium cv. Fancy is an ornamental cactus with a heterogeneous genetic background, which includes variegated variants whose in vitro culture response has not been studied. So plants exhibiting different degrees of variegation (from 0% to 100%) were also classified by their initial size and used to obtain different types of explants (apices, central discs, epicotyls and hypocotyls). The effects of three plant growth regulators (BAP at 8µM, KIN at 4µM and TDZ at 1µM) was evaluated. The response of explants was measured in the number of shoots, calluses and rhizogenesis events per explant; as well as the appearance of variegated shoots with specific color percentages. Central discs treated with 1 µM TDZ provided the best results in terms of shoot production. Additionally, a correlation was observed between the type of activated areole (green, mixed or fully colored) and the percentage of color of the obtained shoots, enabling precise explant selection based on desired morphological characteristics. Additionally, the appearance of shoots with different colors confirms the possibility of selecting new lines from this cultivar. These findings could be of great value not only for breeding and multiplication of ornamental cactaceae but also other edible species and relatives.