17种绣线菊核型特征及核型参数分析

Karyotype Features of 17 Species of Spiraea and Karyotype Parameters Analysis

以17种(品种)绣线菊为材料,利用改良去壁低渗法分析染色体特征并作相关性和聚类分析,探讨核型特征与种间进化关系。研究结果表明:供试绣线菊染色体数稳定,为2n=18和2n=36,染色体基数为9,主要由中部着丝点染色体(m)和近中部着丝点染色体(sm)组成。绒毛绣线菊、石蚕叶绣线菊、楔叶绣线菊染色体中有随体结构;核型类型为1A、1B、2B,染色体平均臂比范围为1.26～1.64,最长与最短染色体比值范围为1.67～3.51,着丝点指数范围为38.96%～44.26%,核型不对称系数范围为56.14%～60.69%;按核型不对称系数从高到低排序其进化程度,石棒绣线菊、绒毛绣线菊和楔叶绣线菊等进化程度高,珍珠绣线菊、石蚕叶绣线菊和三亚绣线菊等进化程度低;核型参数的重要性排序为核型不对称系数>平均臂比>臂比大于2的比率>染色体最长/最短值>核型类型>着丝点指数均值;17种绣线菊核型参数在种间存在差异,可作为绣线菊属植物分类依据;核型特征聚类分析将17种绣线菊分为4组。

17 species of Spiraea were selected as materials,using wall degradation hypotonic method to analyse the features of chromosome,to do associativity analysis and cluster analysis,to discuss the karyotype features and macroevolution.The results suggested that the 17 species of Spiraea had stable chromosome number,2n=18 and 2n=36,basic number of chromosome was 9,their chromosomes were mainly composed by median region chromosome（m）and submedian region chromosome（sm）,in which there were satellites in Spiraea dasyantha,Spiraea chamaedryfolia and Spiraea canescens.Their karyotype types were 1A,1B,2B,their average arm ratio changes from 1.26 to 1.64,Lt/St changes from 1.67 to 3.51,centromeric index changes from 38.96% to 44.26%,A.s.k% changes from 56.14% to 60.69%.We sorted the evolution degree of 17 species of Spiraea from high to low according to the karyotype dissymmetry coefficient,in which S.media,S.dasyantha and S.canescens were high,S.thunbergii,S.chamaedryfolia and S.trilobata were low.The importance of karyotype parameters was A.s.k%〉 A.A.R〉 P.C.A%〉 Lt/St〉 karyotype type〉 centromeric index.There were differences of karyotype parameters in 17 species of Spiraea,karyotype datas could provide a base for the classification of Spiraea.Seventeen species of Spiraea could be divided into 4 groups by karyotype features cluster.