In vitro culture, plant regeneration and clonal behaviour of Sesuvium portulacastrum (L.) L.: a prospective halophyte.

An efficient plant regeneration protocol using axillary shoots of the salt accumulator halophyte, Sesuvium portulacastrum (L.) L. was established and in vitro responses of six Sesuvium clones were studied. The shoot and root induction responses to cytokinins and auxins in clone MH (Maharashtra) were concentration specific. Significantly the highest number of shoots, average shoot elongation and percent shoot regeneration per explant were observed on MS medium supplemented with 40 μM 2-isopentenyl adenine (2iP) followed by 20 μM benzyladenine (BA). Higher cytokinin (60 μM), however, inhibited shoot induction and shoot length. The lower concentrations (5 or 10 μM) of α-napthaleneacetic acid (NAA) proved more effective for root induction, number of roots and average root length. Well-developed plantlets were successfully hardened and established in the field with more than 85 % survival rate. In vitro response of six Sesuvium clones cultured on MS + 20 μM BA revealed higher multiplication rate in clone MH and KA (Karnataka, India) compared to other clones. The results offer the prospect of selecting clones of this species with characteristics desirable for utilization and/or restoration in specific ecological zones.