Multiple shoot regeneration, establishment of callus and cell suspension cultures in Salacia macrosperma Wight

Abstract

Salacia macrosperma Wight. - a potent medicinal plant facing the verge of rare and endemic status to the Western Ghat of southern India. Effective protocol has been established for induction of callus and multiple shoot regeneration using leaf and nodal explants on MS medium fortified with various plant growth regulators like 2,4-dichlorophenoxyacetic acid (2,4-D), benzyl amino purine (BAP), thidiazuron (TDZ), Indole acetic acid (IAA), Kinetin (Kn), Naphthalene acetic acid (NAA) and Indole butyric acid (IBA). Leaf explants produced more calli (98.33%) than nodal explants at 2.5 + 1.5 mg L-1 of 2, 4-D and BAP in combination. MS medium with 1.5 mg L-1 of 2, 4-D, 2.0 mg L-1 of BAP and 1.5 mg L-1 of TDZ along with 1% activated charcoal was apt for multiple shoot regenerations (93.33%) from nodal explants with embryogenic callus. Rhizogenesis was achieved in liquid MS medium supplemented with 1.0 mg L-1 of IAA. Friable callus when agitated in liquid MS medium at 100 rpm embryogenic callus followed by morphological changes were observed. Cytogenetic variations such as multinucleate, multinucleolate, cytodifferentiation, chromosomal bridges were noticed, besides normal dividing stages. Anatomical features were observed by microtome sections of the embryogenic callus revealed the presence of active centers, embryoids, and shoot bud formation. Further, by scanning electron micrograph (SEM) analysis of embryogenic callus different stages of morphogenic developmental features were recorded.