An efficient method for production of diploid Cantaloupe Charentais Melon (Cucumis melo L var. cantalupensis) by somatic embryogenesis

This paper describes a system of regeneration that allows somatic embryo formation at high frequency from mature cotyledon explants of Cucumis melo L. var. cantalupensis (cv. Vedrantais). Several different growth factors, environmental conditions and carbohydrate sources were analysed in order to improve somatic embryogenesis in this cultivar. Best conditions lead to the definition of a two step protocol including a 2 week period of embryogenesis induction in Murashige and Skoog's medium supplemented with 30 g l(-1) glucose, 10 mu M 2,3-dichlorophenoxyacetic acid and 0.5 mu M 6-benzylaminopurine (IM medium) in the darkness, followed by a period of embryo development on the same medium without hormone (DM medium), under a 16/8 h light/dark photoperiod. After 4 weeks of culture, somatic embryos were converted into plantlets on the DM medium in a Magenta vessel. Using this optimized protocol, 42% of the explants were able to generate embryos with an average of 7.8 embryos per explant. More than 60% of the plants generated from these embryos were diploid, exhibited the phenotype expected and gave well-developed fruit. (C) 1997 Elsevier Science B.V.