Genome size variation in the Arternisia arborescens complex (Asteraceae, Anthemideae) and cultivars.

Abstract: Different wild Mediterranean populations of Artemisia arborescens from diverse locations, representing its geographical distribution, as well as some of its well-known cultivars and some specimens cultivated as omamentals in gardens, streets, roads and nurseries, were analysed for genome size estimation. Other closely related species endemic to Macaronesia, A. canariensis, A. argentea and A. gorgonum, were also measured, and their nuclear DNA amount has been related to the biogeography of this group of species. Additionally, five populations of the closely related A. absinthium were analysed to establish comparisons. Measurements, acquired by flow cytometry, ranged from 8.29 pg to 11.61 pg for 2C values. Statistically significant differences of nuclear DNA amounts with respect to factors such as insularity or domestication have been detected. However, a quite low intraspecific genome size variation has been detected in these species. Furthermore, the study also addressed the possible hybrid origins, and possible misidentifications of some of the supposed cultivars ofA. arborescens.