Plant Biol (Stuttg) 2005; 7(4): 397-404
DOI: 10.1055/s-2005-865693
Research Paper

Georg Thieme Verlag Stuttgart KG · New York

Nuclear DNA Content and Chromosome Number in Some Diploid and Tetraploid Centaurea (Asteraceae: Cardueae) from the Dalmatia Region

S. Siljak-Yakovlev1 , M. E. Solic2 , O. Catrice3 , S. C. Brown3 , D. Papes4
  • 1Département Evolution et Systématique, UMR CNRS 8079, Université Paris-Sud, Bât. 360, 91405 Orsay Cedex, France
  • 2Institute “Mountain and Sea”, Franjevacki put 1, 21300 Makarska, Croatia
  • 3Institut des Sciences du Végétal, CNRS UPR 2355, 91198 Gif-sur-Yvette, France
  • 4Department of Molecular Biology, Faculty of Science, University of Zagreb, Roosveltov trg 6, 10000 Zagreb, Croatia
Further Information

Publication History

Received: January 5, 2005

Accepted: March 17, 2005

Publication Date:
18 July 2005 (online)

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Abstract

Given the paucity of information about genome size in the genus Centaurea, nuclear DNA content of 15 Centaurea taxa, belonging to four subgenera and six different sections, has been investigated for the first time. The sample concerns 21 populations from the Dalmatia region of Croatia. The 2C DNA content and GC percentage were assessed by flow cytometry and chromosome number was determined using standard methods. Genome size of studied Centaurea ranged from 2C = 1.67 to 3.72 pg. These results were in accordance with chromosome number and especially with ploidy level that varies throughout this group; 2C DNA values ranged from 1.67 to 3.43 pg for diploid, and from 3.19 to 3.72 for polyploid taxa. No significant intraspecific variations of DNA amount were found between two subspecies of C. visiani and C. ragusina, nor between two varieties of C. gloriosa. However, some populations of C. glaberrima and C. cuspidata showed a significant difference in DNA amount. Three different basic chromosome numbers were observed in studied species (x = 9, 10, and 11). The most frequent basic number was x = 9. C. rupestris, C. ragusina ssp. ragusina, and C. r. ssp. lungensis possessed x = 10 and C. tuberosa x = 11. The species with a basic chromosome number of x = 9 had a small genome size and the smallest chromosomes (on average 0.09 to 0.12 pg/chromosome) but frequently present polyploidy. Centaurea ragusina ssp. ragusina and C. r. ssp. lungensis had a mean base composition 41.3 % GC.