The effects of in vitro salinity (NaCl) on plantlet growth, microtuberization and genetic diversity was investigated under saline and non-saline conditions using twelve cultivars (clones) of potato named Ranger-russet, AGB-69-1, MEX-32, Maine-28, Loman, Araucana INTA, Surena INTA, American-INTA, Aracy, FLS-5, Agria and Marphona, which were planted in the greenhouse. Young shoots were cut and transferred to tissue culture laboratory of agricultural biotechnology research institute. Apical and axillary meristems were cultivated on MS medium and samples were subcultured every four weeks on the same medium for plantlet production. Then plantlets were propagated through single nodal culture. To study the effects of salinity (NaCl) on the growth of single nodal explants and on microtuberization, cultivation on MS media with different concentrations of NaCl (0, 25, 50, 75 and 100 mol l(-1)) was carried out. Growth of single nodal explants on the saline media indicated that all the characters of the cultivars studied, the salinity levels and the studied interaction effects had significant difference at P < 0.01. These characters were also shown to have different responses to salinity levels. Microtuberization responses on different saline media was also different and indicated that all the studied characters, except the number of microtubers and the mean of minimum microtuber diameter, had significant difference at P < 0.01 for cultivars, salinity levels and interaction effects. Genetic diversity on the basis of microtuberization using analysis of cluster among potato cultivars and phenotypic correlations among characters under saline and non-saline conditions were also studied.
