In Vitro Clonal Propagaion of Citrullus colocynthis (Linn.) Schrad.- A Threatened Medicinal Plant

A rapid clonal propagation system has been developed for medicinally potent plant species Citrullus colocynthis (Linn.) Schrad through in vitro culture of mature nodal segments with axillary bud. Maximum number of multiple shoots (43.6 � 0.457) was obtained on MS medium supplemented with BAP (2.0 mg/l) and NAA (2.0 mg/l). In vitro raised elongated shoots (> 8.5 cm) from the cluster were excised and transferred on rooting medium fortified with 4.0 mg/l Indole-3-butyric Acid (IBA). These rooted shoots were successfully acclimatized in pots containing vermi-compost and sterilized soil (1:3). Histological studies revealed direct origin of shoot buds from cultured explants. The study on the profile of isozyme of peroxidases has also revealed differences between in vitro and in vivo plant parts. Isoperoxidase activity was higher in callus as compared to in vitro shoot and in vivo leaf, stem and fruit. Isoperoxidase modifications during morphogenesis of callus and shoot were also observed. In the present study a rapid, reproducible, regenerating protocol for clonal propagation of Citrullus colocynthis through mature nodal explant culture has been established.