SUMMARYThe long arm of barley chromosome 3 can be divided into four segments by three C-band locations. From the centromere the segments comprise 4 per cent, 26 per cent, 34 per cent, and 36 per cent of the arm length. The segregation of 114 F2-plants showed a 1:2: 1-ratio for C-bands at the three locations. No recombination was observed between the two proximal C-band locations whereas the two distal locations recombined with a frequency of 12±2 per cent. The three C-band locations were linked with loci cer-zd, uz, and cer-zn, but not with the tightly linked loci Est-1 and Est-4. The order of and distance (in per cent rec.) among the three cytological markers and the three marker gene loci were: 3l1-<1 per cent -312-2± 1 per cent-cer-zd-2±1 per cent-uz -8±2 per cent-313-16±3 per cent-cer-zn. A comparison of cytological distances and linkage values suggests that recombination is virtually confined to the distal half of this chromosome arm. In addition, C-bands at one location on chromosomes 6 and 7, respectively, segregated in 1 :2: 1-ratios. The C-band location on chromosome 6 and the Amy-i locus were linked with a recombination percentage of 23 3 per cent. The usefulness of multiple marker stocks is discussed.