title: Genome-dependent chromosome dynamics in three successive generations of the allotetraploid Festuca pratensis × Lolium perenne hybrid.
abstract: We focus on the identification of complete and recombined ribosomal DNA-bearing chromosomes, and the dynamics of chromosomal number and position of ribosomal DNA (rDNA) loci in the F2-F4 generations derived from the F1 hybrid of Festuca pratensis Huds. (2n = 4x = 28) × Lolium perenne L. (2n = 4x = 28). Lolium genomic DNA and rRNA genes were mapped by means of genomic and fluorescence in situ hybridization (GISH and FISH). The results revealed that plants of the three generations share various rDNA loci profiles with chromosome structural changes, possibly as a result of chromosomal inter- and intra-rearrangements. We observed an asymmetrical variation in the number of recombinant arms with and without rDNA loci between parental genomes. The Lolium genome was more affected by rearrangements in arms with rDNA loci, while Festuca was more affected in arms without them. Statistically significant differences between L. perenne and F. pratensis genomes concerned the number of recombined chromosomes without rDNA, and the number of recombined rDNA-bearing chromosomal arms of marked chromosomes, showing a tendency of F. pratensis genome-like chromosomes to be less stable, compared with L. perenne. We postulate a novel genome-dependent range and type of chromosome variation in plants of the F2-F4 generations derived from F. pratensis × L. perenne hybrid.
authors.affiliation: Department of Environmental Stress Biology, Institute of Plant Genetics of the Polish Academy of Sciences, Strzeszyńska 34, 60-479, Poznań, Poland, tksi@igr.poznan.pl.
authors.forename: Tomasz
authors.initials: T
authors.lastname: Książczyk
authors.forename: Elżbieta
authors.initials: E
authors.lastname: Zwierzykowska
authors.forename: Katarzyna
authors.initials: K
authors.lastname: Molik
authors.forename: Magdalena
authors.initials: M
authors.lastname: Taciak
authors.forename: Paweł
authors.initials: P
authors.lastname: Krajewski
authors.forename: Zbigniew
authors.initials: Z
authors.lastname: Zwierzykowski
mesh_terms: D032461:Chromosomes, Plant / Q000235:genetics*; D004275:DNA, Ribosomal / Q000235:genetics; D031751:Festuca / Q000235:genetics* / Q000502:physiology; D018745:Genome, Plant / Q000235:genetics*; D008129:Lolium / Q000235:genetics* / Q000502:physiology
chemical_list: D004275:DNA, Ribosomal