This study aimed to investigate the tissue culture and rapid propagation techniques of Orostachys fimbriata, a medicinal and ornamental herbaceous perennial herb belonging to the family Crassulaceae. The leaves of O. fimbriata were used as explants to investigate the effects of plant growth regulators such as thidiazuron (TDZ), 6-benzylamino purine (6-BA) and 1-naphthaleneacetic acid (NAA), on the induction of callus, differentiation of adventitious buds and rooting of shoots. Our results showed that optimum callus induction medium was MS medium supplemented with 0.5 mg•L −1 TDZ and 0.2 mg•L −1 NAA. 1.5 mg•L −1 6-BA and 0.2 mg•L −1 NAA was the optimum hormone combination for differentiation of adventitious buds. And 0.1 mg•L −1 NAA could efficiently promote rooting. The survival rate of transplants reached about 90%. In this study, using leaves of O. fimbriata as explants, high efficient tissue culture and regeneration system of O. fimbriata were established, and the period from leave to transplant plantlet was about 3 months. The presently developed protocol could be used for large scale clonal propagation and germplasm conservation of O. fimbriata. The efficient tissue culture system of O. fimbriata would provide technical support for its utilization.

In the present study, the effect of plant growth regulators (PGRs) on callus regeneration, adventitious shoot differentiation, and root formation of Haworthia turgida Haw. was investigated. The greatest callus induction percentage (95.6%) was achieved with leaf explants inoculated on Murashige and Skoog (MS) medium with 1.0 mg·L−1 6-benzyladenine (BA) and 0.1 mg·L−1 1-naphthaleneacetic acid (NAA), and this callus induction medium supplemented with 2.5 mg·L−1 thidiazuron (TDZ) was optimal for callus proliferation. The maximum number of shoots (25.7) was obtained when the callus was cultured on MS medium supplemented with 1.0 mg·L−1 BA and 0.2 mg·L−1 2,4-dichlorophenoxyacetic acid (2,4-D). The highest number of roots per shoot (6.2) and highest rooting frequency (82.0%) were obtained when adventitious shoots were inoculated on MS medium with 0.05 mg·L−1 NAA. Regenerated plantlets were transferred to a mixture of vermiculite and soil and acclimated in a greenhouse. The survival rate of the transplanted plantlets was about 91.6%. The rate of ex vitro rooting was 83.3%, indicating that this technique is effective for root induction in H. turgida. This study has established a rapid and efficient micropropagation system that can be beneficial for commercial cultivation and germplasm conservation of H. turgida.