In vitro proliferation and ex vitro rooting of microshoots of lisianthus using auxin and cytokinin on the solid, liquid and double-phase culture systems

A protocol was developed for high frequency and low cost of in vitro shoot proliferation and ex vitro rooting of Eustoma grandiflorum (Gentianaceae) on solid medium. Shoot tips as explants were cultured on Murashige and Skoog (MS) medium enriched with different concentrations of 2,4-dichlorophenoxyacetic acid (2,4-D) (0.00, 0.01, 0.10 and 1.00 mg l–1) and 6-benzylaminopurine (BAP) (0.00, 0.50, 2.00 and 5.00 mg l–1). Three culture media systems (solid, liquid and double-phase) were applied. None of the explants cultured on liquid and double-phase media resulted in live plant production. Maximum axillary shoot number (54.45) was recorded in the plantlets treated with 0.10 mg l–1 2,4-D in combination with 5.00 mg l–1 BAP. Treatment of 0.01 mg l–1 2,4-D along with 0.50 mg l–1 BAP produced maximum node number and internode length. Some shoots produced on medium containing plant growth regulators (PGRs) were rooted in soil. The largest number (5.50/plantlet) and longest length of root (7.75 cm/plantlet) were obtained in ex vitro condition on the base of shoots produced in culture medium enriched with 0.10 mg l–1 2,4-D along with 0.50 mg l–1 BAP. The combination of 1.00 mg l–1 2,4-D and 0.50 mg l–1 BAP was found to be the most suitable PGRs for obtaining the highest callus weight. The most fresh weight was calculated from plantlets grown on the medium containing 0.10 mg l–1 2,4-D along with 5.00 mg l–1 BAP. Maximum dry weight was obtained in free-PGRs medium. About 90% of the rooted plantlets were established successfully in cultivation beds. Acclimatized plants were morphologically similar to the mother plants.