不同产地苦参核型及似近系数聚类分析

Analysis of Karyotypes and Resemblance-near Coefficients of Sophora flavescens from Different Producing Origins

目的为探讨苦参核型特征及不同产地来源种质材料间的进化关系。方法本实验以产于内蒙古赤峰、山西长治、陕西眉县和四川成都的苦参为材料,采用根尖压片法,比较分析了苦参的核型特征,并采用核型似近系数聚类分析方法对参试材料进行聚类分析。结果 4个产地苦参的染色体数目均为18,核型公式分别为2n=2x=18=18m(1SAT)、2n=2x=18=14m(1SAT)+4sm(1SAT)、2n=2x=18=16m(1SAT)+2sm和2n=2x=18=18m(1SAT),核型均属1A型;核型不对称系数分别为56.32%、57.88%、59.41%与54.32%,其中成都苦参核型较为原始。核型聚类结果表明,四川成都苦参和内蒙古赤峰苦参的核型似近系数最大为0.992 9,核型进化距离为0.007 2,亲缘关系最近。四川成都苦参和陕西眉县苦参的核型似近系数最小0.953 3,核型进化距离为0.047 8,亲缘关系最远。结论 4种苦参的进化关系为成都苦参的核型最为原始,依次为内蒙苦参、长治苦参和眉县苦参。核型特征将为苦参植物种质鉴定、遗传变异和亲缘关系分析提供细胞学依据。

OBJECTIVE To investigate the karyotype characteristics and evolutionary relationships among the traditional Chinese medicine Sophora flavescens from different producing origins. METHODS The karyotypes and chromosome numbers of Sophora flavescens from four different producing origins were analyzed by using root-tip squashing method and clustered by the karyotype resemblance-near coefficient aimed to establish a genetic link for all the materials. RESULTS The chromosome numbers of Sophora flavescens from Chifeng Inner Mongolia, Changzhi Shaanxi, Meixian Shaanxi and Chengdu Sichuan were all 18, and their karyotype formulas were 2n =2x = 18 = 18m（2SAT） , 2n =2x = 18 = 14m（1SAT） ＋4sm（1SAT） , 2n =2x = 18 = 16m（2SAT） ＋2sm and 2n =2x = 18 = 18m（2SAT） respectively, all of which belonging to 1A type, and karyotype asymmetry index of which were 56. 32% , 57.88% , 59.41% and 54. 32% , and the karyotype of Sophoraflavescents from Chengdu was more primitive among the total. Karyotype clustering analysis showed that the closest genetic relationship existed between S. flavescens from Chengdu and that from Chifeng as their karyotype resemblance-near coefficient was the highest, namely 0. 992 9, and their evolution distance was 0. 007 2. The farthest genetic relationship existed between S. flavescens from Chengdu and that from Meixian with the lowest karyotype resemblance-near coefficient, namely 0. 953 3, and their evolution distance was 0. 047 8. CONCLUSION The karyotype of S.flavescens from Chengdu is the most primitive, followed by those from Chifeng, Changzhi and Meixian. The results of this study provide cytological information for germplasms identification, genetic variation and analysis of genetic relationship of Sophora flavescens.