Regeneration from cotyledon explants of Turkish melon (Cucumis melo var. inodorus and var. reticulatus) cvs. Hasanbey I, Yuva, Kirkagac 637, Topatan, Kuscular and Ananas were investigated. Two regeneration media were used: IK1560 (Moreno et al., Plant Cell, Tissue Organ Cult. 5, 139, 1985). and the regeneration medium of Neidz et al., Plant Cell, Tissue Organ Cult., 18, 313, 1989 (N medium). In vitro cultures were placed in a growth room at 29+/-1degreesC, with 16 h photoperiod and 100-120 mumol m(-2) s(-1) cool white fluorescent light. Regeneration on N medium was higher than on IK1560. Greater regeneration was obtained from explants of 4 and 5-day-old cotyledons than from explants from 6-day-old cotyledons. Kirkagac 637 showed the highest regeneration rate of all the cultivars. Green regenerable callus formation was better on IK1560 medium than on N medium. The cv. Topatan had a higher green callus formation rate than the other cvs. Moreover, the explants originating from N regeneration medium produced more buds and/or shoots on the shoot elongation medium NB00101 (Vallis and Lasa, Plant Cell Rep. 13, 145, 1994) than those from IK1560 regeneration medium.