横断山宽叶变黑蝇子草四个居群的核型研究

Karyomorphological Study on Four Populations of Silene nigrescens subsp.latifolia(Caryophyllaceae)in the Hengduan Mountains

宽叶变黑蝇子草(Silene nigrescens subsp.latifolia)隶属于石竹科(Caryophyllaceae)蝇子草属(Silene),是特产自中国西南横断山高山流石滩地区的物种.利用植物细胞学常规压片技术首次报道了该种4个居群的染色体数目和核型.结果表明,其中三个居群的宽叶变黑蝇子草间期核均为复杂型;另一个居群的间期核则属于简单型.这四个居群的有丝分裂前期染色体均属于中间型.四个居群的宽叶变黑蝇子草染色体数目均为2n=48,染色体核型公式为2n=4x=48=48m,属1A核型,四个居群均为四倍体,该物种的居群间核型变异很小,体现出该种在横断山地区的核型稳定性.

Silene nigrescens subsp. Latifolia belongs to Caryophyllaceae,which is endemic species of the alpine subnival belt from the Southwest China.In this study,the karyotype of four populations of S.nigrescens subsp, latifolia were examined for the first time by root tip squash method.The results showed that the interphase nuclei of three of them were the complex chromosome type,and the simple chromosome type for the rest one.The prophase chromosomes of all four populations were found to be of the interstitial type.A karyotype of 2n=4x=48=48m with type 1A asymmetry for four populations of S.nigrescens subsp, gatifolia .They are all tetraploid species.The karyotype variation of this species is very similar,which reflects the karyotype stability of this species in the Hengduan Mountain.