<i>Cheirolophus intybaceus (Asteraceae, Centaureinae)</i> o la constància del valor 2C

Abstract

Cheirolophus intybaceus (Asteraceae, Centaureinae) or the constancy of 2C value.- Cheirolophus intybaceus is a heliophyte growing in thermal Mediterranean scrublands along a coastal belt of 50 km large, stretching from Toulon (France) to the Southern part of the Iberian Peninsula, occurring also in the Balearic Islands (with the exception of Minorca). Moreover, this species is also growing in high and sunny lands in the Mediterranean river basins, consti- tuting a complex of taxa closely related among them. The objectives of this work are: i) to provide new genome size data for some Asteraceae species; ii) to study the variation of DNA amount along a species distribution area; iii) to evaluate the discrimination capability of this parameter at low taxonomic levels. A signio cantly positive correlation between the DNA amount and the latitude has been found, that is, in drier and warmer habitats genome size tends to decrease in this species. The variation in the whole distribution area of Ch. intybaceus is 1.15-fold. This low variability supports the constancy of 2C-value. Abstract Cheirolophus intybaceus (Asteraceae, Centaureinae) or the constancy of 2C value.- Cheirolophus intybaceus is a heliophyte growing in thermal Mediterranean scrublands along a coastal belt of 50 km large, stretching from Toulon (France) to the Southern part of the Iberian Peninsula, occurring also in the Balearic Islands (with the exception of Minorca). Moreover, this species is also growing in high and sunny lands in the Mediterranean river basins, consti- tuting a complex of taxa closely related among them. The objectives of this work are: i) to provide new genome size data for some Asteraceae species; ii) to study the variation of DNA amount along a species distribution area; iii) to evaluate the discrimination capability of this parameter at low taxonomic levels. A signio cantly positive correlation between the DNA amount and the latitude has been found, that is, in drier and warmer habitats genome size tends to decrease in this species. The variation in the whole distribution area of Ch. intybaceus is 1.15-fold. This low variability supports the constancy of 2C-value.