Light and scanning electron microscopic analysis of benzyl adenine induced multiple shoot regeneration in kenaf (Hibiscus cannabinus L.)

Abstract

Morphological changes in shoot apices of kenaf treated with benzyl adenine (BA) were compared with those of untreated control plants using light and scanning electron microscopy (SEM). Seven days after the start of BA treatment (day 7), meristematic regions appeared adjacent to the axillary buds, and on the abaxial surface of the primary leaf primordia. Some of these meristematic regions were later developed into shoots. Further, the cells in the primary shoot apical meristem were reprogrammed to induce several meristematic loci. At day 28 in culture, supernumerary vegetative shoot buds were observed in and near the axillary buds. In the control plants neither axillary nor adventitious buds developed. These results suggest that the treatment with BA reprogrammed the developmental fate of a large number of cells in the shoot apex of kenaf. Further, it reconfirmed the ability of BA to overcome the apical dominance of shoots.