High frequency plant regeneration from shoot tip explants of Citrullus colocynthis (Linn.) Schrad. – An important medicinal herb
A high frequency and rapid regeneration protocol was developed from shoot tip explants of Citrullus colocynthis on Murashige and Skoog (MS) medium supplemented with N6-benzylamino-purine (BAP, 0.5 mg/l) and α-naphthalene acetic acid (NAA, 0.5 mg/l). Highest number of shoots (23.0 ± 0.567) was obtained on MS medium containing BAP (0.5 mg/l) and NAA (0.5 mg/l). The regenerated shoots were further elongated on same medium. In vitro shoots were excised from shoot clumps and transferred to rooting medium containing indole-3-butyric acid (IBA, 4.0 mg/l) with 0.2% activated charcoal. The rooted plants were hardened in polycups containing sterile soil and vermiculite and finally well established in the field; survival rate was 60%. This is the first report of direct in vitro plantlet regeneration in C. colocynthis from shoot tip explant.
Key words: Citrullus colocynthis, regeneration, shoot tip.