Optimization of conditions for in vitro seed germination and shoot multiplication of Aconitum heterophyllum Wall

Aconitum heterophyllum is a critically endangered medicinal plant species of Indian Himalayas. Micropropagation of this plant is considered important for its ex-situ conservation as well as to generate large scale planting material for commercial supply. During the present study, seeds were taken as starting material. Seeds of A. heterophyllum are associated with a dormancy period and so optimization of conditions was needed for in vitro germination. Mechanical scarification of seeds by rubbing between hands (to crack the seed coat randomly) reduced the microbial contamination and was also found essential for germination, as seeds with no mechanical treatment could not germinate. Further, germination could be observed only on cotton moistened with distilled water; MS medium was found inhibitory for in vitro seeds germination. The soaking of seeds at low temperature (4oC) for 72 hours, before culturing, enhanced the germination frequency to 95.83%. Amongst various parts of seedling used for in vitro shoot induction, shoot organogenesis was obtained only from plumule tip and that too on MS media with 0.5ml/l BAP.