High Frequency Plant Regeneration and In Vitro Flowering of Regenerated Plantlets of Spilanthes acmella Murr. - An Important Threatened Bio-Insecticide Medicinal Plant

摘要

An efficient micropropagation protocol was developed for the medicinal plant Spilanthes acmella Murr., using shoot tip and nodal segments for multiple shoot proliferation. Maximum multiplication (7.0 shoots) per explant was observed on MS medium supplemented with 2.0 mg/L BA and 0.1 mg/L NAA. Frequency of multiplication was increased in subsequent subcultures. Rooting was achieved using MS medium containing Indole-3-butyric acid. Shoots that were in vitro rooted resumed growth after a short period ofacclimatization and resulted in plantlets, which were successfully established in soil. In vitro flowering was observed in some of the nodal explants and also in shoots derived from leaf explants through direct regeneration on MS medium with different concentrations and combinations of cytokinins BA and Kin or 2-iP along with either IAA or NAA or GAa. Histological studies were carried out to elucidate the ontogeny of flower of tissue cultured and field grown plants. Seed setting was observed in flowers in vitro. Seed setting in mature flowers was well displayed.