Karyological analysis of some Achillea L. (Asteraceae) taxa

The genus Achillea L. (Yarrow) belonging to family Asteraceae (Compositae) is distributed in mostly Eurasia, some parts of North Africa, North America and Southern Hemisphere. It is known that genus has approximately 140 species troughout the world. In Turkey it is represented by totally 50 taxa, 44 of are species. In this study, 6 Achillea taxa (A. biebersteinii, A. cappadocica, A. falcata, A. millefolium subsp. millefolium, A. nobilis subsp. neilreichii, A. setacea) were investigated karyologically.The chromosome numbers of the taxa studied have been determined as 2n = 2x = 18 (A. biebersteinii, A. falcata, A. nobilis subsp. neilreichii ve A. setacea), 2n = 4x = 36 (A. cappadocica) and 2n = 7 - 8x = 67 (A. millefolium subsp. millefolium).The chromosome number of Achillea cappadocica have been reported for the first time with this study. It was showed that there was not any variation in the basic chromosome number (x = 9) in the genus. Median and submedian centromered chromosomes were determined in karyotypes of investigated taxa. The chromosome morphologies of all taxa except Achillea falcata and A. nobilis subsp. neilreichii have been determined firstly.It was determined that total karyotype length was important in the closely related taxa have different ploidy level.Key Words: Achillea, Asteraceae, Karyology, Chromosome Number, Polyploidy, Cytotaxonomy