Micropropagation of Banana Varieties (Musa spp.) Using Shoot-Tip Culture

A study was carried out at the Tissue Culture Laboratory of Melkassa Agricultural Research Centre, Ethiopian Institute of Agricultural Research (EIAR) to investigate the effects of different types and concentrations of cytokinin's and auxins on shoot initiation and multiplication, and in vitro shoot rooting of three banana varieties using shoot-tip explants. Shoot initiation was greater on Murashige and Skoog (MS) basal medium supplemented with 3 mg/l N6-benzylaminopurine (BAP) for Dwarf and Giant Cavendish while 2 mg/l for Poyo varieties. Among the different concentrations of plant growth regulators (PGR) tested, MS medium supplemented with combinations of BAP and indole-3-acetic acid (IAA) at 3+0.4, 4+0.4 and 3+0.2 mg/l for Dwarf, Giant and Poyo respectively, were best combinations for high rates of shoot proliferation and elongation. Further multiplication of shoots required up to 5 times sub culturing of 1 month each on the same media combination. In this study, about 3-fold multiplication rate was achieved during every subculture. Better rooting was obtained when the shoots were cultured on MS medium with 2.12 mg/l α-naphthaleneacetic acid (NAA) for Dwarf and Giant while 1.74 mg/l indol-3-butyric acid (IBA) for Poyo. In vitro rooted plantlets were transferred to the lighthouse for acclimatization and hardening. The best growth was recorded for plantlets transplanted on potting media containing a 3:1 ratio (v/v) of sugarcane filter cake and sand. The hardened plants were transferred and well established to the field.