In-vitro propagation and phytochemical profiling of a highly medicinal and endemic plant species of the Himalayan region (Saussurea costus).

Efficient protocols for callus induction and micro propagation of Saussurea costus (Falc.) Lipsch were developed and phytochemical diversity of wild and in-vitro propagated material was investigated. Brown and red compact callus was formed with frequency of 80-95%, 78-90%, 70-95% and 65-80% from seeds, leaf, petiole and root explants, respectively. MS media supplemented with BAP (2.0 mgL-1), NAA (1.0 mgL-1) and GA3 (0.25 mgL-1) best suited for multiple shoot buds initiation (82%), while maximum shoot length was formed on media with BAP (1.5 mgL-1), NAA (0.25 mgL-1) and Kinetin (0.5 mgL-1). Full strength media with IAA (0.5 mgL-1) along with IBA (0.5 mgL-1) resulted in early roots initiation. Similarly, maximum rooting (87.57%) and lateral roots formation (up to 6.76) was recorded on full strength media supplemented with BAP (0.5 mgL-1), IAA (0.5 mgL-1) and IBA (0.5 mgL-1). Survival rate of acclimatized plantlets in autoclaved garden soil, farmyard soil, and sand (2:1:1) was 87%. Phytochemical analysis revealed variations in biochemical contents i.e. maximum sugar (808.32 µM/ml), proline (48.14 mg/g), ascorbic acid (373.801 mM/g) and phenolic compounds (642.72 mgL-1) were recorded from callus cultured on different stress media. Nonetheless, highest flavenoids (59.892 mg/g) and anthocyanin contents (32.39 mg/kg) were observed in in-vitro propagated plants. GC-MS analysis of the callus ethyl acetate extracts revealed 24 different phytochemicals. The variability in secondary metabolites of both wild and propagated plants/callus is reported for the first time for this species. This study may provide a baseline for the conservation and sustainable utilization of S. costus with implications for isolation of unique and pharmacologically active compounds from callus or regenerated plantlets.