Abstract: Karyotypes of 6 species in Angelica L . from Sichuan are studied at population level and the karyotype of A. pseudoselinum is firstly reported . It is found that the number of chromosomes are invariably 2n = 2x =22 , with most of them are median and submedian centromeric chromosomes, while subterminal centromeric chromosomes exist in A. omeiensis . The majority of karyotypes belong to 2A, and Shihuiyao population of A. laxifoliata has 1A types . As for karyotypic formula , A. omeiensis is 2n =22 = 10m+ 2sm+ 10st , A. maowenensis is 2n =22= 16m+ 4sm+ 2sm (SAT) , A. sinensis is 2n = 22 = 14m+ 8sm, A. apaensis is 2n = 22 = 14m+8sm, and A. pseudoselinum is 2n =22 = 12m+ 8sm+2sm (SAT ) . However, different populations of A. laxiforliata don’t have the same karyotypic formulae, and there are some variations between the caryotypes more or less . According to Stebbins, A. omeiensis’s evolution status was showed by the highest index of asymmetry among six species studied in this paper , while A. laxiforliata is a little primitive because of its lower index of asymmetry and its 1A caryotypes . However , the morphological, anatomic , karyotypic characters and that of pollen grains are evolving asynchronously , suggesting that, Sichuan as one of the frequency centers of Angelica L . in China , is also one of the differentiation centers of Angelica L .

Key words: Angelica

摘要： 从居群水平对四川当归属(Angelica L .) 6 种植物的核型进行了研究, 其中管鞘当归核型为首次报道。6 个种的染色体均为2n = 2x = 22 , 多为中部和近中部着丝粒染色体, 核型多为2A 型, 仅疏叶当归石灰窑居群为1A 型; 峨眉当归核型为2n = 22 = 10m+ 2sm + 10st , 茂汶当归核型为2n = 22 = 16m+ 4sm+ 2sm (SAT) , 当归核型为2n = 22 = 14m + 8sm, 阿坝当归核型为2n = 22 = 14m + 8sm, 管鞘当归核型为2n = 22 = 12m+ 8sm+ 2sm (SAT) , 而疏叶当归不同居群的核型或多或少发生了不同程度的变异。参照Stebbins 的观点, 峨眉当归以核型不对称系数最高而在6 个种中显示一定的核型进化性, 疏叶当归不对称系数较低, 且出现1A 型核型因而体现出一定的原始性。但是, 综合形态解剖、花粉性状以及核型特征可以看出, 四川当归属植物各性状间具有进化的不同步性, 这也表明, 作为当归属分布频度中心之一的四川地区, 同时也是当归属的分化中心之一。

关键词: 当归属, 染色体,  , 核型FONT