Chromosome numbers and morphology of eighteen Anthemideae (Asteraceae) taxa from China and their systematic implications

The chromosome number and morphology of eighteen taxa belonging to seven genera in Anthemideae endemic to China were investigated using karyological technique. Chromosome numbers of six species i.e. Aja� nia khartensis (Dunn) C. Shih (2n=4x=36), A. potaninii (Krasch.) Poljakov (2n=2x=18), A. remotipinna (Hand.- Mazz.) Y. Ling ex C. Shih (2n=2x=18), Phaeostigma variifolium (Chang) Muldashev (2n=2x=18), Achillea acumi� nata (Ledeb.) Sch. Bip (2n=2x=18) and A. wilsoniana Heimerl ex Hand.-Mazz. (2n=4x=36) are firstly reported, and new ploidy level of A. fastigiata (C.Winkl.) Poljakov (2n=4x=36) and Hippolytia alashanensis (Y. Ling) C. Shih (2n=2x=18) is reported for the first time. The further karyological studies show that most of the studied taxa have more symmetrical karyotype 2A (that of N. pectinata is 1A), and only Jingyuan (JY) population of A. przewalskii and A. remotipinna have more asymmetrical karyotype 2B. The correlations among the ploidy, geographic distribu- tion and morphology are further discussed.