Cell Suspension Cultures and High Frequency Shoot Regeneration of Some Hypericum species

The Hypericum genus is significant both medically and economically due to its bioactive compounds. This study utilized plant biotechnology techniques to develop an efficient and reliable adventitious shoot regeneration and suitable cell suspension culture system for various Hypericum species, including Hypericum perforatum L., Hypericum leptophyllum Hochst, Hypericum heterophyllum L., Hypericum humifusum L., and Hypericum athoum Boiss. & Orph. High frequency of callus induction using leaf explants on MS medium containing 1.0 mg/L BAP and 0.1 mg/L 2,4-D for Hypericum perforatum L. (100%), Hypericum humifusum L. (90%), and Hypericum leptophyllum Hochst (90%). The best shoot regeneration was also achieved in Hypericum humifusum L. (86.3%), Hypericum perforatum L. (73.0%), Hypericum leptophyllum Hochst (45.67%) and Hypericum athoum Boiss. & Orph. (18.33%) on MS medium with 1.0 mg/L BAP and 0.1 mg/L 2,4-D. Calli clusters obtained on callus induction medium were cultured on cell suspension culture MS basal media with B5 vitamins containing 2 mg/L glycine, 1 mg/L 2,4-D, 0.1 mg/L KIN, and 0.1 mg/L BAP. The friable calli developed in the suspension culture and plated on the medium. The proembryogenic structures formed turned to embryonic structures. These globular embryos further transformed into heart and cotyledonary stage and germinated. The maximum number of shoot/callus or percentage of germination of somatic embryo were respectively recorded for H. perforatum L. (15.37/callus), H. leptophyllum Hochst (6.9/callus), H. heterophyllum L. (9.6/callus), H. humifusum L. (16.8/callus) and H. athoum Boiss. & Orph. (11.7/callus). H. perforatum L. and H. humifusum L. showed the best shoot regeneration capacity as recorded in adventitious shoot regeneration studies. The plants were acclimatized with 85-100 % survival rat, H. perforatum and H. humifusum L. had also the highest survival rate (100%) as having regeneration capacity.