In vitro regeneration of Ensete ventricosum from zygotic embryos of stored seeds

Abstract

Plant regeneration through in vitro germination and the production of adventitious shoots from zygotic embryos was investigated using stored seeds of two enset genotypes (Mariya and Oniya), as germination of intact seeds could not be achieved. The seeds were decontaminated before and after water pretreatment and the embryos cultured on MS medium. Germination was studied with vertical and horizontal embryo orientations, on three media compositions: MS medium, MS with 0.5 mg l− 1 BA + 0.2 mg l− 1 lAAand MS with 0.5 mg l− 1 BA + 0.2 mg l− 1 2,4-D. Treating seeds of the Oniya clone with distilled water before decontamination and excision of embryos caused extensive contamination of cultured embryos. Decontamination without water pretreatment showed only about 5% contamination. Contamination was low with Mariya but no germination occurred. Horizontal embryo orientation resulted in better germination for Oniya. Supplementing MS medium with BA and IAA improved germination of the excised embryos (44%) and promoted formation of multiple shoots and simultaneous initiation of callus in some embryos. Subculturing the callus on the same medium composition (MS with BA + IAA) resulted in more and earlier initiation and proliferation of organogenic callus in the dark than other media compositions. Adventitious shoots were regenerated in the light on MS medium lacking plant growth regulators. Proliferation of a watery and friable callus was better when 2,4-D (0.2 mg l− 1) was added in the presence of BA and IAA during subculturing.