<i style="mso-bidi-font-style: normal">In vitro</i> plant regeneration of <i>Citrullus colocynthis </i>(L.) Schard. and assessment of genetic fidelity using ISSR and RAPD markers

Abstract

<i style="mso-bidi-font-style:normal">In vitro</i> plant regeneration protocol has been developed for <i style="mso-bidi-font-style:normal">Citrullus colocynthis </i>(Linn.) Schrad. using nodal segments and shoot tip explant cultures. The impact of different concentrations and combinations of auxins and cytokinins was evaluated for direct and indirect shoot bud induction and proliferation. Multiple shoot bud induction and proliferation occurred on MS medium fortified with BA (2.2 µM). Shoot buds were subcultured to multiplication medium containing BA (2.2 µM) for proper growth and elongation of shoots. Rooting was readily achieved upon transferring the shoots on to ½ strength MS medium supplemented with IBA (4.9 µM). Micropropagated plantlets were hardened in the greenhouse and successfully established in soil. The genetic fidelity of <i style="mso-bidi-font-style:normal">in vitro</i>-raised clones was assessed by using random amplified polymorphic DNA (RAPD) and inter-simple sequence repeat (ISSR) markers. Out of 20 RAPD and 20 ISSR primers screened, only 12 RAPD and 8 ISSR primers produced clear, distinct and scorable bands with an average of 5.5 and 6.5 bands per primer, respectively. The number of bands generated per primer was greater in ISSR than RAPD. All banding profiles from micropropagated plants were monomorphic and similar to those of the mother plant. This confirmed the true-to-type nature of the <i style="mso-bidi-font-style:normal">in vitro</i>-raised clones.