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This study aimed to establish an efficient culture media for in vitro conservation of uninodal segments of the species Dioscorea alata, D. bulbifera, D. rotundata and D. trifida, for a 7 months period; by modifying MS media culture with the following osmolytes: sucrose, mannitol and sorbitol: Six treatments (T) were evaluated in the following percentages: T1 (3% sucrose), T2 (1.5% mannitol), T3 (2% sorbitol), T4 (1.5% sucrose + 1.5% mannitol), T5 (1.5% sucrose + 2% sorbitol) and T6 (mannitol 1.5% + 2% sorbitol). Treatments were evaluated every 30 days for: survival (%), expanded leaves (%), length of stem and roots, number of leaves, shoots and roots, phenolization (%), leaf senescence (%) and callus (%). The results showed that Dioscorea alata and D. bulbifera are better conserved using the combination mannitol-sorbitol (1.5-2%), while D. rotundata and D. trifida, adequately respond to the individual use of mannitol (1.5%) and sorbitol (2%) respectively. In conclusion these sugars, and their combination, allow extended subculture periods, supporting the effective conservation of yams, using stem node explants; ensuring a reduced growth rate of the plantlets, with a high survival rate and viability of the species evaluated. [ABSTRACT FROM AUTHOR]