Optimized In vitro Propagation, Acclimatization and Reintroduction of Endemic Rhododendron inaequale Hutch. from Northeast India

Rhododendron inaequale Hutch., an endemic plant with high economic potential and susceptibility, requires urgent conservation measures. This study aimed to develop an optimized in vitro propagation protocol for this species. In vitro seed germination was conducted using Anderson medium, Woody Plant Medium (WPM), and MS Medium. WPM supplemented with 8 mg L⁻¹ 2iP [N6-(2-Isopentenyl) adenine] yielded the highest multiple shoot induction (3.55 ± 0.14 shoots, 0.77 ± 0.03 cm shoot length). For rooting, WPM with 0.5 mg L⁻¹ IBA [Indole-3-butyric acid] produced the maximum number of roots (3.40 ± 0.43) with a mean root length of 1.84 ± 0.12 cm. Successfully acclimatized plants were reintroduced into natural habitats in various locations in Meghalaya and Nagaland. Additionally, 200 micropropagated plants were distributed for further conservation initiatives. This study provides a crucial protocol for the conservation and reintroduction of R. inaequale, aiding in the preservation of this vulnerable species.