Enhanced somatic embryogenesis under salt stress condition in Justicea gendarussa

Somatic embryogenesis is a desirable morphogenetic pathway that allows regeneration of plantlets in a single step, thereby avoiding the complicated rooting step to recover plants from regenerated shoots. Leaf explants of Justicea gendarussa were inoculated on Murashige and Skoog's medium (Murashige and Skoog 1962) containing 2 mg/l 2, 4-D and different concentrations of one of the three salts-NaCl, KCl, Na₂SO₄. Explants were subjected to salt stress in two ways-gradual treatment and shock treatment. The callus produced in both cases were subcultured using a diverse range of media, with and without salt and it was found that the morphogenetic path that the surviving cells adopted was somatic embryogenesis. Somatic embryos were formed in large numbers in the salt tolerant calli and showed bipolarity on germination.