The type of explant plays a determining role in the micropropagation of Ensete ventricosum

Abstract

Three to five shoots per shoot tip were produced when in vitro-grown zygotic seedlings of enset genotype Oniya were used as donor plants and the shoot tips split longitudinally through the apex into two and cultured on a basal Murashige and Skoog (MS) medium supplemented with 11 μM BA and 6 μM IAA. Only one shoot per shoot tip of greenhouse-grown suckers was regenerated from about 60% of the explants on a similar medium, while the remainder died, presumably due to blackening and necrosis of the tissues. Increasing the BA concentration from 11 μM to 22 μM or to 44 μM did not increase to the number of shoots from the halved shoot tips. On MS medium supplemented with 11 μM BA and 6 μM IAA or 5 μM NAA, the intact shoot tip gave rise to a single shoot that originated from the apical bud. From the intact shoot tips that were grown in vitro on medium with 44 μM, 89 μM, 178 μM, 266 μM, 355 μM and 444 μM BA, 72% gave rise to a single shoot/bud from the apical bud without induction of any lateral buds, while the rest produced one or two lateral buds that were mainly hyperhydric. Therefore, wounding the apical dome by splitting appears necessary to release lateral buds from apical dominance of the tip of the monopodial corm of enset during micropropagation. The greater response in production of multiple shoots by zygotic seedlings cultured in vitro could be due to the absence of blackening and the juvenile nature of the explants.