Non-embryogenic synthetic seed production of Lawsonia inermis L. and HPTLC analysis of lawsone

An attempt was made to standardize a protocol for synthetic seed production and subsequent plant regeneration of Lawsonia inermis by calcium alginate encapsulation of both in vivo and in vitro regenerated axenic nodal segments. The combination of 3% sodium alginate and 100 mM CaCl₂ was found as the optimum encapsulation matrix showing the highest sprouting (73.3%), and germination rate (66.6%) for synthetic seed derived from in vivo nodal explant and highest sprouting (80%), and germination rate (70%) for synthetic seeds derived from in vitro nodal explants on Murashige and Skoog’s (MS) basal medium. It was confirmed that the synthetic seeds could be stored at 4 ºC up to two weeks without losing much of their germination potential i.e., about 56.6% and 66.6% germination was recorded for in vivo and in vitro nodal explants encapsulated synthetic seeds respectively. Lawsone is the most important compound present in L. inermis. Thus, the biochemical fidelity of the plants derived from synthetic seeds (encapsulated axenic in vitro nodal explant) vis-a-vis the mother plant was confirmed by checking the lawsone through HPTLC. This standardized protocol for synthetic seed production of L. inermis could be utilized for the exchange and transfer of germplasm to distant places or laboratories as well as for its propagation. At the same time, this protocol of synthetic seed production could be useful for the production of biochemically identical and stable plants of L. inermis, in terms of lawsone, for pharmaceutical and cosmetic industries.