Tuberisation under salt stress of potato vitroplants (Solanum tuberosum L.). In Chott-Mariem (Tunisia), potato plants of Claustar variety, regenerated in vitro from a salt-adapted cal (3 g.l-1 of NaCl) and cultivated in presence of NaCl concentration of 4 g.l-1 have tuberised. These adapted plants were as outstanding as plants regenerated from a control cal and irrigated with NaCl-free water, relating to the number of tubers per plant and the average fresh weight of tuber. However, tubers of NaCladapted plants have shown a reduction in diameter and bud number, and they were affected by a deep fissuring when grown under irrigation with saline water. These results suggest that increasing the level of organic matter above 1 % in soil can be recommended in order to overcome such abnormalities, caused by salinity and saline water use (3 to 4 g.l-1 of NaCl) in the Sahel region (Mahdia, Monastir and Sousse).