Submitted to: Meeting Abstract
Publication Type: Abstract only
Publication Acceptance Date: 6/15/2003
Publication Date: 9/8/2004
Citation: Tuna, M., Vogel, K.P., Arumuganathan, K. 2004. Cytogenetic characterization of tetraploid bromus ciliatus genome. Meeting Abstract. Proceedings of the 17th EUCARPIA General Congress, Sept 8-11, Tulln, Austria. Abstract p. 503. Interpretive Summary: Tetraploid Bromus ciliatus L. is a North American bromegrass. The objective of this study was to characterize the genome of the tetraploid B. ciliatus by cytogenetic methods and compare it to other Bromus species. The results of this study indicate that tetraploid B. ciliatus has different genomes than the European species of bromegrass that have been evaluated such as widely grown smooth bromegrass, Bromus inermis.
Technical Abstract: Tetraploid Bromus ciliatus L. is a North American bromegrass. The objective of this study was to characterize the genome of the tetraploid B. ciliatus by cytogenetic methods and compare it to other Bromus species. All the plants of the accession (USDA PI 232214) that were evaluated were tetraploids (2n = 28). The mean 2C nuclear DNA content for B. ciliatus was 19.13 ± 0.07 pg as determined by flow cytometery. C-banding procedures were used to identify individual mitotic chromosomes and to develop a karyotype for B. ciliatus. The genome of the tetraploid B. ciliatus consisted of 16 median chromosomes, 8 submedian chromosomes and 4 chromosomes with satellites including one pair with a large satellite and one pair with a small satellite. The general pattern of the distribution of constitutive heterochromatin in B. ciliatus was quite different than the other bromegrasses that have been analyzed to date including B. inermis, B. riparius, B. erectus, and B. variagatus. Except two pairs of chromosomes, all chromosomes in tetraploid B. ciliatus had telomeric bands on one or both arms. Some of the chromosomes with telomeric bands had centromeric bands situated at one or both sides of the centromere and intercalary bands which were generally absent in the other bromegrass species. It was possible to identify all chromosomes of tetraploid B. ciliatus and to match the pairs of homologous chromosomes by using chromosome lengths, arm length ratios and C-banding patterns. The results of this study indicate that tetraploid B. ciliatus has different genomes than the European species evaluated to date in the section Pnigma.