Abstract: This is the first report of the chromosome karyotype of P. anomala from the Altai populations. The populationssampled from the Altai region of Xinjiang , China , are diploid ( 2n = 10) , with the 2A type karyotype and the karyotypic
formula of 2n = 2x= 10 = 6m+ 2sm+ 2st . Based on karyotypic and asymmetric parameters, i . e ., mean arm ratio , ratioof longest􊄯shortest chromosomes (L1/Ln ) , coefficient of karyotypic overall asymmetry (CKOA) , it was found that therewas no apparent differentiation in karyotype features among all the three sections of the genus Paeonia , although someslight karyotypic differences were found between the woody section ( Sect. Moutan DC .) and the herbaceous sections(Sect . Onaepia Lindley and Sect. Paeonia) . The diploid status of the P . anomala populations , revealed in this study, implies that the species, assumed as interspecific hybridization origin , may add to the handful examples of homoploid hybridspeciation in angiosperms .

Key words: Paeonia

摘要： 报道了Paeonia anomala L. 的核型, 澄清了新疆阿尔泰地区分布的该物种的染色体数目。分布于该地区的Paeonia anomala L. 的核型组成: 2n = 2x = 10 = 6m+ 2sm+ 2st。该类群核型与该属其它类群一致———2A 型。在综合比较分析该属染色体参数以及核型不均一性数, 包括最长􊄯最短染色体比(L1/Ln ) 和染色体不对称系数( CKOA) 的基础上, 我们发现该属三个组在核型上没有明显分化, 仅在木本类群(Sect . Moutan DC .) 和草本类群(Sect. Onaepia Lindley 和Sect. Paeonia) 之间存在微小差异。此外, 作为二倍体类群, 新疆阿尔泰地区分布的Paeonia anomala L. 很可能是二倍体杂种, 这将为研究被子植物的父母本同倍化杂交式物种起源提供一个很好的研究材料。

关键词: PaeoniaEM, 核型, 染色体不对称系数FONT