Preliminary responses of 2, 4-D and BAP on callus initiation of an important medicinal-ornamental Hymenocallis littoralis plants

Abstract

Hymenocallis littoralis locally known as Melong kecil is an ornamental plant traditionally believed to have medicinal properties. This study was done to identify the best concentration and combinations of plant growth regulators (PGRs) for the initiation and production of friable callus. Four (4) weeks old plant was used in this study. Bulb was dissected and cleaned (sterilized) using standard surface sterilization technique and then cultured in semi-solid Murashige and Skoog (MS) media with combinations of 6-Benzylaminopurine (BAP) and 2, 4-D hormones at different concentrations ranging from 2.25 to 22.50 µM. The best concentration for callus induction was determined by using percentage of callus induction. The optimum concentration for callus initiation was obtained by using 13.50 µM of 2, 4-D and 4.50 µM of BAP with 93.75% of callus induction rate. However, concentration 22.50 µM of 2, 4-D and 9.50 µM of BAP produced the lowest callus induction at 12.50%. The earliest time period, which is needed to initiate callus from the meristematic tissue was obtained at 15 days on semi-solid MS media with 13.50 µM of 2,4-D and 4.50 µM of BAP. In contrast, culture medium with 18.00 µM of 2, 4-D and 9.00 µM of BAP took 40 days from inoculation to produce callus. Culture medium containing 9.00, 13.50 and 18.00 µM of 2,4-D together with 4.50 µM of BAP produced yellow friable callus whereas the other concentrations produced yellow compact calluses. Hence, 13.50 µM of 2,4-D and 4.50 µM of BAP concentration is the best medium for callus induction for H. littoralis. Key words: Hymenocallis littoralis 2, 4-D, benzylaminopurine (BAP), bulb, callus initiation.