Journal of Applied Horticulture. 2002: 4(2): 77-82

Induction of caulogenesis and somatic embryogenesis in Cucumis melo (var. flexuosus)

Mohsen Hanana; Moncef Harrabi; Mohamed Boussaid

Laboratoire de Genetique et Amelioration des Plantes, Institut National Agronomique de Tunis (INAT), 43 Avenue Charles Nicolle, 1002 Tunis, Tunisia.

Within the framework of genetic improvement of Tunisian Snake-melon (Cucumis melo) cultivar by biotechnological methods, we have developed a method to regenerate whole plants by in vitro culture using cotyledon and hypocotyl as explants on MS medium with different combinations and concentrations of auxin and cytokinin. Adventitious buds were initiated from hypocotyls grown on medium with 1.5 mg 2,4-D/litre and 0.5 mg benzyladenine/litre. A maximum percentage of embryogenesis (20%) was obtained for cotyledons grown in MS medium containing 0.5 mg 2,4-D/litre and 1 mg kinetin/litre. For stimulating the development of adventitious buds and the embryo's germination and their conversion into plants, MS medium diluted twenty times and supplemented with 1.5% sucrose was used. Histological studies showed that adventitious buds were initiated from the peripheral zones of the organogenic calluses by aggregation of meristematic cell masses which organized into a typical shoot meristem. Embryoids resulted from the division of cells with a dense cytoplasm, a large nuclei and a thick wall which are differentiated on the callus periphery.