Nuclear DNA content in the polyploid complex Turnera ulmifolia (Turnera L., Passifloraceae).

LÓPEZ, ALICIA; PANSERI, ANDREA FLORENCIA; POGGIO, LIDIA; FERNÁNDEZ, AVELIANO

PLANT SYSTEMATICS AND EVOLUTION

SPRINGER WIEN

Año: 2011 vol. 296 p. 225 - 230

0378-2697

Turnera ulmifolia constitutes a well studied polyploid complex with allo- and auto-polyploidsspecies ranging from 2x to 8x. Flow cytometry was used to determine nuclear DNA content and toestimate 2C and 1Cx-values with the aim of analysing the genome size in Turnera under the view ofpolyploid speciation. The 2C-value and 1Cx-value were evaluated in 12 species of the T. ulmifoliacomplex. Nuclear DNA content was estimated by flow cytometry of nuclei stained with PropidiumIodide. The 2C DNA content ranged from 1.38 to 1.83 pg in diploids, from 2.67 to 3.96 pg. in tetraploids,from 2.73 to 4.31 pg. in hexaploids, and from 3.53 to 5.90 pg. in octoploids. The 1Cx-value ranged from0.44 to 0.99 pg. Turnera ulmifolia complex showed an increase in total DNA-content with the ploidylevel, but not in the expected proportion. The general tendency indicated a decrease in the 1Cx-valuewith increasing chromosome number, with T. grandidentata 4x being an outstanding exception. The1Cx-values in the allooctoploids T. aurelii and T. cuneiformis differed by 1.6-fold from each otherprobably as a result of different evolution processes from a common origin.