9种松属植物的核型及亲缘关系

摘要

By tablet production technology and AI Cytovision, we studied the karyotype of nine kinds of Pinus, and explored their evolutionary trends and interspecific genetic relationship.Nine species have the same karyotype formula of 2n=2x=24=24m, and all the karyotype belong to Type 1A.The asymmetrical karyotype coefficient is in 52.37%-53.16%, the mean arm ratio is in 1.114-1.150, the ratio of the longest chromosome to the shortest is in 1.491-1.742, and the mean of centromere index is in 46.64%-47.42%.The relative length formula on chromosome of P.thunbergii is 16M2+6M1+2S, 14M2+10M1 for P.armandii, and 14M 2+8M1+2S for the others.By the asymmetrical karyotype coefficient and scat-ter diagram, we obtained the degree of the karyotype asymmetry for nine species of Pinus, P.kesiya var.langbianensis is the hightest and the most evolutionary relatively, the second is P.densata, and P.armandii is the most original.By clus-tering resultsof SPSS 18.0, P.armandii of the Subgen Strbus has relatively far distance with the other eight species of the Subgen Pinus in the genetic relationship, and can be clustered into one group.The other eight are divided into two catego-ries:P.thunbergii, P.massoniana, P.densiflora and P.taeda are in one category, and P.tabulaeformis, P.yunnanen-sis, P.densata and P.kesiya var.lagn bianensis are in another category.%采用压片制片技术，通过AI Cytovision软件研究了9种松属植物的核型，并对它们的进化趋势及种间亲缘关系进行探讨。结果表明：9种松属植物的核型公式均为2n＝2x＝24＝24m，核型类型均属于Stebbins 核型分类标准中的1A型；核型不对称系数变化范围52．37％～53．16％，平均臂比1．114～1．150，染色体长度比1．491～1．742，着丝点指数均值范围46．64％～47．42％；黑松染色体相对长度组成为16M2＋6M1＋2S，华山松为14M2＋10 M1，其余种均为14 M2＋8 M1＋2 S。由核型不对称系数和核型不对称性程度散布图得出，思茅松核型不对称程度最高，相对最为进化，其次是高山松，华山松（ Pimus armandii）最为原始。 SPSS18．0类平均法聚类结果显示：单维管束松亚属的华山松与其它8种双维管束松亚属的种距离相对较远，亲缘关系远，被单独聚为一类。其它8种被分为两类，即黑松（ Pinus thunbergii）、马尾松（ P．massoniana）、赤松（ P．densiflora）和火炬松（ P．taeda）为一类；油松（ P．tabulaeformis）、云南松（ P．yunnanensis）、高山松（ P．d ensata）和思茅松（ P．kesiya var．langbianensis）为一类。