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-specific due to the rate of amplification and extent of divergence. Two genome-specific probes from the genomic DNA library of Festuca arundinacea var. genuina Schreb. were selected and characterized. TF521 was found to be P genome-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 only weakly, with tetraploid Festuca species. TF521 hybridized only with the diploid Festuca and not with the Lolium species (LL). TF436 was specific to tetraploid species of Festuca, such as F. arundinacea var. glaucescens Boiss. (G(1)G(1)G(2)G(2)) and Festuca mairei St. Yves (M1M1M2M2). By means of Southern hybridization, TF436 was used to detect chromatin introgression of F. mairei in the progenies of the hybrid F. maireixLolium perenne L. Potential addition and translocation lines were identified in the BC1F1 derivatives of F. maireixL. perenne. In situ hybridization was used to confirm the genetic identity of these lines. Sequence analyses indicated that TF436 and TF521 were two novel DNA sequences as no homologous sequences were found in Genebank.