A karyological study has been carried out on 6 populations of Aconitum brachypodum across its distribution region. All populations of the Aconitum brachypodum studied are diploid (2n=2x=16) with various chromosome morphologies. Karyological studies have been also carried out on 4 closely related species: A. pseudostapfianum, A. vilmorinianum var. altifidum, A. pukeense, A. ludlowii, A. pendulum and A. brachypodum var. laxiflorum, it is first time to conduct karyological studies on the first 4 species. All 7 species studied are thus diploid with the chromosome number of 2n=2x=16. Combining the available chromosome studies, the Aconitum has relatively consistent chromosome diversification with a basic number of 8, and most species contain diploid individuals, which suggested Aconitum is at the initial phase of polyploid diversification.
1.Yunnan Univ, Sch Life Sci, Kunming 650091, Yunnan, Peoples R China 2.Yunnan Univ Tradit Chinese Med, Kunming 650500, Yunnan, Peoples R China 3.Chinese Acad Sci, Kunming Inst Bot, Kunming 650204, Yunnan, Peoples R China