Barley lines with different size of <duplicated segments> of the short arms of the chromosome 6 and 7 were investigated under greenhouse and field conditions. The objective of the study were morphological features plant fertility and their dependence on the size of a duplicated segment of chromosome and on conditions of plant growth and development. Generally, duplicated lines under field conditions were observed to have a reduced stem lenght, spike size and spike fertility. The largest reduction of all the studied morphological features occurred in the line 9D with the largest duplicated segments, wheras the smallest differences compared to the normal karyotype were in the line 7D with the smallest duplicated segments. It was found that a bigger duplicated segment made large differences in parameters of morphological features manifested under various growth conditions (particularly in plant height). The results indicate that fertility and investigated morpholofgical features of plants with duplicated chromosome segments are affected not only by the absolute amount of genetic material, but also by the structure of translocated chromosomes building up individual karyotypes.