Induction of Meristematic Nodular Calli from Various Explants of Lilium spp. and Long Term Stability in Plant Regeneration Ability and Ploidy Level of the Calli

Abstract

Meristematic nodular calli (NOD) were successfully induced from various plant parts such as seeds, flower organs, shoot apices, stem segments and bulb scales of Lilium spp. on media containing 1 mg/l picloram alone or in combination with 1 mg/l cytokinin. In L. longiflorum, green friable callus (FC) was also induced from bulb scales. Suspension cultures established from both NOD and FC showed high proliferation rate. NOD retained high regeneration ability as well as stable ploidy level during the culture for more than 4 years, while the suspension culture of FC became tetraploid. Protoplasts were efficiently isolated from NOD in some species and cultivars after long term subculture in suspension cultures and the plants were successfully regenerated from the protoplasts of L. x formolongi.