Alien introgressions are often used to introduce beneficial traits from one species into another. However, exploitation of the introgressions in breeding requires proper transmission of introgressed segments to consecutive generations. In introgression cultivars of xFestulolium hybrids, we observed about 27–32% elimination of Festuca chromatin in a single round of multiplication. At this pace, Festuca chromatin would be probably completely eliminated in about four generations of seed multiplication. Thus, it seems that amphiploid forms of xFestulolium with relatively stable hybrid genomes may be more promising material for future breeding than introgression lines.