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

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.

Centaurea rupestris L.: Cytogenetics, Essential Oil Chemistry and Biological Activity

“…Both samples possessed 2n = 20 chromosomes. These results are consistent and in compliance with previously reported genome size and chromosome number for this species approving that plant material used for the both samples was authentic C. rupestris (Siljak Yakovlev, 2005). [25] Centaurea rupestris EO from two different localities was investigated on the chemical composition using GC/MS and results are presented in Table 1.…”

“…In botanical authentication of plant material, together with morphological traits, a genome size, the amount of DNA in the un-replicated haploid nucleus of an organism, are important biological traits used for plant characterization. [23][24][25] To the best of our knowledge this is the first report on C. rupestris biological activity of EO. The evaluation of chemical composition of C. rupestris essential oil and its microbiological validation data will hopefully assist in the identification of promising chemical structures towards life-threatening microbes.…”

Chromosome number and ploidy level in seven Centaurea species from Croatia

“…The chromosome number 2n = 18 reported here confirms the number given by several authors (IPCN 1979;Siljak-Yakovlev 2005; Siljak-Yakovlev & al. 2010), but tetraploid chromosome number (2n = 4x = 36) is also reported by Kuzmanov & al.…”

Diploid and Tetraploid Cytotypes of Centaurea stoebe (Asteraceae) in Central Europe: Morphological Differentiation and Cytotype Distribution Patterns

“…This coincides with the findings by Bancheva and Greilhuber (2006), who determined monoploid genome size of diploids and tetraploids of C. stoebe from Bulgaria as 0.883 pg and from Austria as 0.79 pg. Similarly, a decrease in the nuclear DNA content in tetraploids when compared to the diploids is known also in other species of the genus Centaurea (Siljak-Yakovlev et al 2005;Bancheva and Greilhuber 2006). Also more generally, additivity in genome size of polyploids relative to diploid progenitors can be expected, but does not always occur.…”