title: Isolation and characterization of chromosomal markers inPoa pratensis.
abstract: BACKGROUND
  Poa pratensisL. is a turf grass and forage crop used worldwide. Being a facultative apomictic species,P. pratensishas a highly variable chromosome number. Chromosomal markers constitute a powerful tool for chromosome identification and for various aspects of genomic research. However, currently, no chromosomal markers are available forP. pratensis.
  
  
  RESULTS
  Four novel chromosome markers were isolated from a screen of Cot-1 DNA libraries, combined with fluorescence in situ hybridization (FISH) inPoa pratensis. Three tandemly repetitive sequences (PpTR-1,PpTR-2, andPpTR-3) were characterized as subtelomeric. Monomers of 318 bp, 189 bp and 189 bp were identified inPpTR-1,PpTR-2, andPpTR-3, respectively. One tandemly repetitive sequence (PpCR-1) was shown to be centromeric or pericentromeric, and it had a monomer of 27 bp. The distribution patterns ofPpTR-1,PpTR-2, andPpTR-3 were highly conserved across differentP. pratensiscultivars and in the distantly relatedPoaspecies, whereasPpCR-1 was conserved across differentP. pratensiscultivars, but less conserved acrossPoaspecies.
  
  
  CONCLUSIONS
  In this study, we report the identification and characterization of four novel chromosomal markers inP. pratensis. These chromosomal markers are powerful tools for accurate assessment of chromosome count, genomic and phylogenetic analyses, as well as studies of apomixis inP. pratensis.
authors.affiliation: Key Laboratory of Adaptation and Evolution of Plateau Biota, Northwest Institute of Plateau Biology, the Chinese Academy of Sciences, Xining, 810008 China.
authors.forename: Yanyan
authors.initials: Y
authors.lastname: Zhao
authors.affiliation: Key Laboratory of Adaptation and Evolution of Plateau Biota, Northwest Institute of Plateau Biology, the Chinese Academy of Sciences, Xining, 810008 China.
authors.forename: Feng
authors.initials: F
authors.lastname: Yu
authors.affiliation: Key Laboratory of Adaptation and Evolution of Plateau Biota, Northwest Institute of Plateau Biology, the Chinese Academy of Sciences, Xining, 810008 China.
authors.forename: Ruijuan
authors.initials: R
authors.lastname: Liu
authors.affiliation: Key Laboratory of Adaptation and Evolution of Plateau Biota, Northwest Institute of Plateau Biology, the Chinese Academy of Sciences, Xining, 810008 China.
authors.forename: Quanwen
authors.identifier: 0000-0001-5910-6270
authors.initials: Q
authors.lastname: Dou
keywords: Chromosomal markers; Poa pratensis; Repetitive sequence