Use of genome-specific repetitive DNA sequences to monitor chromatin introgression from Festuca mairei into Lolium perenne

Repetitive DNA sequences contribute considerably to an understanding of the genomes of higher plants. Repetitive DNA sequences tend to be genome-speci fic due to the rate of amplification and extent of divergence. Two genome-s pecific probes from the genomic DNA library of Festuca arundinacea var. gen uina Schreb. were selected and characterized. TF521 was found to be P genom e-specific since it was able to hybridize with Festuca pratensis Huds. (PP) and Festuca arundinacea var. genuina (PPG(1)G(1)G(2)G(2)), but not, or onl y weakly, with tetraploid Festuca species. TF521 hybridized only with the d iploid Festuca and not with the Lolium species (LL). TF436 was specific to tetraploid species of Festuca, such as F. arundinacea var. glaucescens Bois s. (G(1)G(1)G(2)G(2)) and Festuca mairei St. Yves (M1M1M2M2). By means of S outhern hybridization, TF436 was used to detect chromatin introgression of F. mairei in the progenies of the hybrid F. maireixLolium perenne L. Potent ial addition and translocation lines were identified in the BC1F1 derivativ es of F. maireixL. perenne. In situ hybridization was used to confirm the g enetic identity of these lines. Sequence analyses indicated that TF436 and TF521 were two novel DNA sequences as no homologous sequences were found in Genebank.