The effect of different concentrations of growth regulators on the micropropagation of Haworthia attenuatae (zebra haworthi)

Due to the problems of sexual and asexual reproduction of Haworthia attenuatae as one of the most popular ornamental succulents, the possibility of micropropagation of this plant in in vitro conditions was studied. The effect of BAP (Benzylamino purine) and Kin (Kinetin) (0.5, 1 and 2 mg/l) in Combination with IBA (Indole-3-acetic acid) (0, 0.01, 0.1 and 0.5 mg/l) using leaf explants on the shoot regeneration of this plant showed that the highest number of shoots (5.22) was obtained with entire leaf explants on modified MS medium supplemented with 2 mg/l BAP and 0.01 mg/l IBA. Maximum number of leaves (4.66) and the longest and widest leaves (1.05 and 0.68 cm) were produced using entire leaf explants with 0.5 BAP mg/l and 2 mg/l plus 0.5 mg/l IBA, respectively. Whereas, the highest number of regenerated shoots (3.5), the longest (1.45 cm) and the widest shoots (0.87 cm) were observed in combination 1 mg/l Kin with 0.1 mg/l IBA with basal leaf segment explant. The results of root regeneration in modified MS and ½MS media supplemented with 0, 0.5, 1, 1.5 mg/l IBA showed that the highest number of roots (6.66), the longest root (3.47 cm) were observed in ½MS medium supplemented with 1 and 1.5 mg / l IBA, respectively. From the rooted plantlets, 90% of them were adapted to the greenhouse environment. Generally, further optimization of this protocol can be led to using leaf explant for commercial micropropagation of Haworthia attenuata.