167 recombinant inbred lines (RIL) derived from a cross between Tadmor (drought tolerant) and Er/Apm (susceptible) was used. Tadmor, a two-row variety selected from a Syrian landrace, is characterized by high yield stability (Grando 1989) and a high osmotic adjustment capacity (Teulat et al. 1997). Er/Apm, a two-row variety adapted to moderate rainfall conditions (Acevedo 1987), was developed by ICARDA (International Center for Agricultural Research in the Dry Areas, Syria), Recombinant inbred lines were advanced by bulk until the F4 generation at ICARDA and then by single-seed descent until the F8 generation at CIMMYT (Mexico). Linkage analysis and map construction were performed by using Map Manager QTX14 (Manly and Cudmore 1997) using the Haldane function (Haldane 1919) to convert the recombination frequencies to centiMorgans (cM). Acknowledgments: Most of the mapping was done in ENSAM-INRA Montpellier (France) by Beatrice Teulat with technical help from Christiane Borries, under scientific supervision of Dominique This. This work was funded by several grants from INRA France and the French Ministry of Agriculture, and a grant from the EC INCO-DC international cooperation with developing countries program. Contributions to the RFLP data were made by Mireille Khairallah (CIMMYT, Mexico) and Philippe Leroy (INRA, Clermont-Ferrand, France). Ayman Diab and Mark Sorrells (Cornell U., USA) added 33 markers corresponding to candidate genes and ESTs and performed the final map construction. The marker and map data are kindly provided by GrainGenes.