Abstract:W7984 , a synthetic hexaploid wheat, was generated via a cross of the diploid D genome progenitor of cultivated wheat, Triticum tauschii (Coss.) Schmal. with the CIMMYT durum (AABB) variety PR88-89, using the durum as the female parent. The synthetic was then crossed with the hexaploid spring wheat cultivar "Opata85" and the F2 progeny was advanced by single-seed descent to F7. RFLP mapping was carried out on a set of 114 of the resulting inbred lines. Maps of all chromosomes were constructed, including 918 RFLP markers . The population and the parents were used in a hydroponic experiment with nitrogen (N) sufficient (4.0 mmol/L) and deficient (0.4 mmol/L) treatments. After culture for 4 weeks, chlorophyll content in leaf was measured. Via these maps, QTL were identified and digenic interactions were analyzed for chlorophyll content in leaf. The results showed that, under N sufficient environment, 7 QTL were identified, explaining 4.30% to 13.45% of the variation; the 2 parents contributed almost the same effects to the chlorophyll content. Under N deficient environment, 9 QTL were found, explaining 4.04% to 11.73% of the variation. The effects were mostly contributed by the parent W7984, indicating that the progenitors had important contributions to the chlorophyll content under N deficient stress; and chlorophyll content was also influenced significantly by digenic interactions. It was noticeable that 1 locus under N sufficient level and 2 loci under N deficient affected both the shoot dry matter yield and the chlorophyll content, suggesting that there were fundamental links between the chlorophyll content and the dry matter yield. This research may be helpful to understand the genetic background of chlorophyll content in wheat under different levels of N supply.