Restorative Morphogenesis in vitro in the Annual Medic in the Presence of Benzylaminopurine

Abstract

Four annual medic species (Medicago orbicularis (L.) All., M. rigidula (L.) Desr., M. scutellata (L.) Miller, and M. rugosa Desr.) were used as model objects for studying the spectrum of morphogenetic reactions in vitro. The seeds were incubated on nutrient media with benzylaminopurine at different concentrations until germination and, thereafter, the explants of seedlings were cultivated in order to obtain primary calluses and morphogenetic structures. Normal and abnormal (with reduced root and/or apex) seedlings were cultivated in the presence of benzylaminopurine. Further cultivation of explants from the seedlings of both types showed a considerable intra- and interspecific polymorphism by the capacity for callusogenesis, frequency of primary restorative reactions, and pattern of microreproduction in vitro. In the control (the seeds were incubated on a hormone-free medium), no cases of microreproduction by way of organogenesis or somatic embryogenesis were observed. In all experimental variants, the restorative reactions preceded microreproduction in vitro.