Developmental Stage Significantly Affects In Vitro Propagation Practices: A Case Study in Paris polyphylla Smith, an Important Endangered Medicinal Plant of Himalayas

Numerous bioactive chemicals that are necessary for various therapeutic formulations are known to be produced by the rhizomes of Paris polyphylla Smith. Steroid saponins, which can be divided into two main groups: diosgenin (Dio) glycosides and pennogenin glycosides, are the active ingredients in P. polyphylla. It is difficult to propagate using traditional methods because of its slow rate of multiplication and intricate life cycle. Consequently, the goal of the current study is to gain a comprehensive understanding of the effects of rhizome age on P. polyphylla in vitro propagation techniques. Following acid hydrolysis, the methanolic extract of reproductive staged rhizomes showed the highest extraction yield (23.33 +/- 0.57%) when compared to extracts from juvenile and vegetative stages, according to phytochemical analysis. Similarly, it was observed that total antioxidant activity, total phenolic, flavonoid, and diosgenin contents were significantly increased with the age of plant. Moreover, it was shown that the diosgenin content changed according to the plant's growth stage. Among the various factors tested during in vitro establishment studies, maximum shoot regeneration was observed on half-strength MS medium containing 3% sucrose, 2.27-mu M TDZ, and 2.70-mu M NAA using rhizome bud explants. In vitro shoot multiplication was achieved via lateral bud production using higher sucrose (6%) concentration on half-strength MS medium. The in vitro regenerants were further rooted and hardened successfully. This is the first report demonstrating the impact of variable factors that are crucial during the in vitro propagation procedures through lateral bud and mini-rhizome production including growth phase, culture conditions (photoperiod and temperature), MS stock strength, sucrose concentrations, decapitation, various combinations and concentrations of plant growth regulators and growth additives. These results show how the growth phase affects this significant medicinal plant's ex situ conservation and provide a possible protocol for its large-scale in vitro production in a constrained amount of time and space. The findings will be contributing in bringing a balance in the demand-supply statistics of P. polyphylla, and ultimately aid in conservation and management practices of plant resources in the natural habitat.