In-Vitro Evaluation of Salinity Tolerance at Plantlet Growth Stage and Microtuberization in some Potato Cultivars

To study the In-vitro effects of salinity (NaCl) on the plantlet growth and microtuberization in potato, 12 potato cultivars Ranger-russet, AGB-69-1, MEX-32, Marine-28, Loman, Araucana INTA, Surena INTA, American-INTA, Aracy, FLS-5, Agria and Marphona provided by Seed and Plant Improvement Institute were planted in the greenhouse. Apical and axillary meristems were cultivated on MS medium with 2.5 mg l-1 GA3 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, they were cultured on MS media with different concentrations of NaCl including 0, 25, 50, 75 and 100 m mol l-1. Growth of single nodal explants on the saline media indicated that all the characters differed significantly among cultivars, salinity levels and interaction effects. Microtuberization was also affected by salinity level. All the studied characters, except the number of microtubers and the mean of minimum microtuber diameter, were significantly different cultivars, salinity levels and interaction effects. By increasing salinity level, growth of potato plantlets and microtuberization were severely inhibited, and all measured characters were negatively affected, except root dry weight and leaf area which were increased in all cultivars.Under saline conditions, wild-type cultivars (Surena-INTA, American-INTA and Marine-28) performed better than commercial cultivars (Ranger-russet, Agria and Marphona).