An experiment was carried out at the laboratory of tissue culture, Horticulture Dept., college of Agric., University of Baghdad, to evaluate the effect of salt stress on vegetative characteristics of four potato cultivars plantlets (Agria, Ajeba, Mondial and Desiree). five concentration of NaCl (0, 25, 50, 75 and 100 mM/ l) and/ or Na2SO4 (0, 12.5, 25, 37.5 and 50mM/l ) were supplemented to the vegetative growth medium.
Results could be summarized as follows :
Application of 25 mM NaCl/ l to the growth medium increased, number of shoots /plantlet (5.67) and dry weight of shoots and roots (0.022, 0.013 gm), whereas, concentration of 50-100 mM NaCl /l had inhibitory effect on vegetative growth. The Na2SO4 application at 12.5 mM/ l on the other hand, increased slightly (non significant) vegetative growth characteristics, while the concentration 25-50 mM Na2 SO4 L had deliterious effect on shoot and root growth .Shoot content of chlorophyll was decreased while proline content was increased as the concentration of either salt was increased .Desiree and Mondial had the greatest shoot growth ,while Ajeba and Agria had the lowest . The interaction between the two salts on vegetative growth was significant where, the greatest number of shoots was found when 25 mM NaCl with 12.5 mM NaSo4 l were added whereas ,highest dry weight of shoots and roots , and shoot content of chlorophyll a and total were resulted from the application of 25mM NaCl with no application of Na2SO4 highest concentration of both salts resulted in highest content of proline in the shoots. Desiree cultivar treated with 25mM NaCl l had the greatest number of shoots and dry weight of roots.