Micropropagation and confirmation of genetic homogeneity in Magnolia punduana (Hook. f. & Thomson) Figlar-a threatened endemic plant

Magnoliapunduana (Hook. f. & Thomson) Figlar is an endemic threatened taxon from Meghalaya that has been exploited heavily for its high-quality timber. The species has been listed as threatened (data deficient) in the IUCN RED list owing to its habitat destruction, fragmentation, and poor regeneration in the wild. Alternative measures like micropropagation becomes essential to raise M. punduana clones. To achieve this, micropropagation protocol was developed from nodal segments of young and mature M. punduana. The single primer amplification reaction (SPAR) method was employed to confirm the genetic uniformity among the regenerants. Induction of microshoots was achieved within 12-15 d of culture on Murashige and Skoog (MS) medium supplemented with 0.5 mu M 6-benzylaminopurine (BAP). For shoot proliferation, microshoots were subcultured on half strength medium (half MS medium) supplemented with 0.5 mu M BAP and 8.0 mu M indole butyric acid (IBA). Regenerated shoots were best rooted on half MS medium fortified with 10 mu M IBA. Acclimatization and final establishment of rooted plantlets were done on potting mixture of soil, sand, and perlite (1:1:1 v/v/v) with 80% survivability rate. The SPAR method revealed a monomorphism rate of 97.11% among regenerants derived from young mother plant (P1) explants while plantlets derived from mature mother plant (P2) explants showed 95.69% monomorphism. Jaccard's similarity coefficient had similar findings showing maximum genetic homogeneity among plantlets derived from younger plant. Such high level of genetic uniformity confirmed through SPAR therefore ensures the success of the micropropagation protocol to be released for raising true-to-type genotype which may be utilized in the future by concerned stakeholders for clonal forestry, phytochemical extraction, pharmacognosy, and conservation.