Karyotype of endangered medicinal plant Aconitum brachypodum, and its afinis species A. pendulum and A. brachypodum var. laxi florum.

A karyological study has been caried out on six populations of Aconitum brachypodum across its distribution region (Dongchuan,Huize,Lijiang,Ninglang, Yanyuan and Muli). Al populations of the A. brachypodum studied were diploid (2n=2x=16) with various chromosome morphologies A. brachypodum has relatively consistent chromosome diversification with a basic number of 8. Only the karyotype formulas of Ninglang and Yanyuan populations were same. The kartotype of Muli population belonged to Stebbins' 1A type,the kartotype of Lijiang, Ninglang, Yanyuan populations belonged to Stebbins' 2B type,and the kartotype of Huize,Dongchuan populations belonged to Stebbins' 3B type. Six populations in A. brachypodum had different karyotype and they al belonged to comparatively asymmetric type. The karyotype formula of A. pendulum is 2n=16=8m+8sm, and the karyotype formula of A. brachypodum var. laxiflorum is 2n=16=10m+6sm. The variation of the karyotype formula, As.K.% and AI did not show clear and corespondingly geographical distribution. And six populations did not contain polyloid individuals, the breeding of A. brachypodum need to be studied in the future. [ABSTRACT FROM AUTHOR]