DArT technology was applied to a tetraploid (2n = 4x = 28) L. multiflorum´F. glaucescens hybrid lineage over ten generations. By selecting 151 Lolium- and 210 Festuca-specific DArT markers among the 3,884 ones developed by Kopecký et al. (Development and mapping of DArT markers within the Festuca–Lolium complex, BMC Genomics 10:473, 2009), it is shown that DArT polymorphism is well consistent with the history of the plant material and the events in relation with interspecific hybridisation: amphiploidisation, introgression into 4x- and 2x-L. multiflorum, reduction of effective size, chromosome mapping as well as parent-specific response to summer water deficit. In this respect, frequency of Festuca markers within a 4x-BC1 population was found to have increased on average by 2.4 % among plants having survived in sward after summer while frequency decreased by 10.2 % after three generations of seed multiplication from the initial polycross of BC1 parents.