In vitro propagation and genetic fidelity analysis of alginate-encapsulated Bacopa monnieri shoot tips using Gracilaria salicornia extracts

The scope of the present study is to investigate the effect of plant growth regulators and seaweed liquid extracts (SLEs) on in vitro regeneration of the Ayurvedically important memory plus plant Bacopa monnieri using shoot tips. Sodium alginate-encapsulated shoot tips were cultured on Murashige and Skoog (MS) medium containing 6-benzylaminopurine (BAP), kinetin, zeatin, 1-naphthaleneacetic acid (NAA), indole-3-acetic acid (IAA), and indole-3-butyric acid (IBA), individually for shoot initiation. The effect of Gracilaria salicornia and Kappaphycus alvarezii SLEs (20–80 %) for shoot induction and regeneration using shoot tips was also studied. MS medium containing 1.0 mg L⁻¹ BAP and 0.5 mg L⁻¹ NAA showed highest multiple shoot induction frequency 95.8 %, mean number 147.8, and mean length 12.5 cm of shoots where G. salicornia extract at 60 % showed 85.9 % multiple shoot induction with 145.6 shoots and mean length 12.3 cm after 5 weeks of incubation. An effective rooting frequency 84.1 % was observed on half-strength MS medium containing 0.1 mg L⁻¹ IAA and where 25 % of G. salicornia extract showed 82.2 % of rooting after 1 week of incubation. In vitro-rooted plants were acclimatized in soil cups and maintained in greenhouse with natural conditions. In vitro-propagated and mother plants were analyzed using random amplified polymorphic DNA markers reveled that no genetic variation between control plants and in vitro-regenerated plants using SLEs. These results showed that G. salicornia extracts can be used as PGRs for in vitro propagation of B. monnieri and it is a simple, rapid mass propagation method.