Lindernia manilaliana Sivar., a rare, endangered and threatened (RET) aquatic plant included in red list category of IUCN and facing the threat of extinction, is reported to be endemic to Kerala. The leaf and nodal explants showed direct regeneration on MS media and developed multiple shoots. Nodal explants from basal medium when sub-cultured onto MS medium supplemented with BAP and KN alone or in combination with BAP, KN and NAA showed multiple shoot proliferation of 81.5±7.5 plantlets from single explants within 4 weeks. Tender leaves from in vitro-grown plants induced direct somatic embryos, which subsequently developed into normal seedlings, similar to those derived from zygotic embryos, at a rate of 50.5 ± 8.6 onto MS medium supplemented with BAP (0.5 mg/L). For rooting, MS medium supplemented with IBA (0.5 mg/L) was found to be the most suitable. Anatomical studies revealed the differentiation of somatic embryos from the leaf midrib and lamina, supported by well-developed vascular structures. In vitro propagation has proven to be a potential technique for large-scale production of planting material for the conservation and reintroduction of the aquatic RET species Lindernia manilaliana.
