Resumen:
The Asteraceae are one of the largest families of angiosperms, comprising 24,000 to 30,000 species in over 1,600 to 2,000 genera. It has a worldwide distribution, with the exception of Antarctica and includes many economically important species which are used, for example, as foods, medicines, and ornamentals. Asteraceae species are the target of many evolutionary studies and more recently they have also become the focus of new genome sequencing programs. New model species for evolutionary-developmental (evo-devo) research have been selected within the Asteraceae such as Gerbera, Helianthus, and Senecio, whereas Tragopogon is the focus of intensive studies on polyploidization mechanisms. The first evo-devo studies in the Asteraceae have been very promising despite complications arising from the genetic and epigenetic changes associated with polyploidy which is very frequent in the family. The term ``C-value¿¿ was coined by Swift to define the gametic nuclear DNA content (genome size) expressed in picograms. Nowadays, genome size research covers a large and diverse range of biological fields and extends across all plant groups. For example, studies have been carried out on genome size nomenclature, to improve methodological aspects and to find possible explanations of how and why genome size changes occur in plants. Data on nuclear DNA amounts are interesting not only per se but are also of practical use. For instance, the success of techniques such as AFLPs and nuclear microsatellites are influenced by genome size, while the choice of a species for possible genome sequencing or evo-devo project is also determined, in part, by genome size. Interest in genome size has increased over the years and this has led to the development of several related databases. Following on from our own research studies on genome size in the Asteraceae family and given that the family is one of the most intensely studied from many aspects, we have developed a genome size database focused specifically on the Asteraceae (which we have named the ``Genome size in the Asteraceae database¿¿, GSAD). It is hoped that this will become a significant tool for comparative research and for future genome size studies.
