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

Lugar: Viena; Año: 2011 vol. 296 p. 225 - 230

0378-2697

Abstract Turnera ulmifolia constitutes a well-studied polyploid complex with allo- and autopolyploid species ranging from 2 to 8x. Flow cytometry was used to determinenuclear DNA content, and to estimate 2C- and 1Cxvalues with the aim of analysing the genome size in Turnera in terms of polyploid speciation. The 2C-value and 1Cx-value were evaluated in 12 species of the T. ulmifolia complex. Nuclear DNA content was estimated by flowcytometry of nuclei stained with propidium iodide. 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 from 0.44 to 0.99 pg. The Turnera ulmifolia complex showed an increase in total DNA content in the ploidy level, but not in the expected proportion. The general tendency indicated a decrease in the 1Cx-value with increasing chromosome number, with T. grandidentata 4x being an outstanding exception. The 1Cx-values inthe allooctoploids T. aurelii and T. cuneiformis differed by 1.6-fold from each other, probably as a result of different evolutionary histories following divergence from the last common ancestor.