Morphogenetic plasticity of callus reinitiated from cell suspension cultures of the fern Platycerium coronarium

Abstract

Cell suspension cultures were initiated from gametophyte-derived callus of the fern Platycerium coronarium. Two distinct types of callus masses, distinguished by their colouration, were obtained when the cells from suspension culture were plated on semisolid Murashige and Skoog (MS) medium containing 10 μM kinetin. The two types of callus masses had distinct morphogenetic capacities despite their common origin. Morphogenesis into either gametophytes or sporophytes occurred when these callus masses were cultured on phytohormone-free MS medium depending on the type of callus used. The dark-green gametophytic callus showed a faster rate of growth and morphogenesis as compared to the pale-green sporophytic callus. Total chlorophyll content and auto fluorescence and size of chloroplasts of the sporophytic callus and cell suspension cultures were lower than that of the gametophytic callus. Observations from con focal laser scanning microscopy were in agreement with the physiological parameters measured. The availability of cell cultures of the same ploidy level, but with two distinct pathways of development will be useful for comparative studies of developmental plasticity.