Author : Kongsakdi Promtep

Summary : Two sets of experiments were conducted to explore the potential of IN VITRO method for propagating excised embryo and shoot tip of Strelitzia reginae. The excised embryo germinated readily in White's medium without vitamins in seven days. Compared to other basal media tested, highly modified Murashige and Skoog's medium (MS) enhanced the growth of seedlings. With MS basal media, the growth of seedlings from embryos was accelerated when treated with a combination of Nephthalene acetic acid (NAA) and coconut water. There was synergistic effect of these two substances in terms of enhanced shoot growth and fibrous root formation. Kinetic (Ki) enhanced the growth of shoot and root. Although benzyl adenine (BA) also enhanced shoot growth, if inhibited root elongation. Callus formation from shoot tip was enduced by sequential culture in media with a combination of BA and NAA, followed by modified Scherck and Hilderbrandt's (SH) medium. Three types of calluses were found: friable, water-soaked, and surface calluses. All types, however, failed to show sustained growth and differentiation. The increase in shoot number sometimes occurred in cytokinin treatments. Combination of Ki and 2, 4-dichlorophenoxy acetic acid (2,4-0) or modified SH and MS medium induced bud formation, but at a low frequency. Half shoot tips could be used successfully for the IN VITRO multiplication of S. reginae. Results showed that embryo and tissue culture could be more promising than the other conventional methods of multiplying S. reginae. Embryo culture could induce faster growth and higher germination rate. The limited success in callus induction and bud proliferation also indicate the possibility of developing a better method of clonal propagation and mass production of this kind of plant in the future.