烟草属植物遗传多样性和亲缘进化关系的荧光AFLP分析

【目的】研究烟草属不同亚属以及不同类型栽培烟草的遗传相似性关系,为明确烟草野生种和栽培烟草的遗传多样性水平、研究栽培烟草起源演化提供依据。【方法】利用CEQ8000遗传分析系统,对烟草属内4种类型的5份栽培烟草以及28份烟草野生种进行荧光AFLP分析,估算其遗传相似系数,并对28份烟草野生种、5份栽培烟草及其可能的祖先种分别进行UPGMA聚类分析。【结果】利用10对AFLP引物在33份种质中共扩增到2 423个片段,2 394个具有多态性。烟草属33份种质的遗传相似系数在0.021—0.860,平均为0.269。当相似系数为0.309时,28份野生烟草按其亚属聚为3类。2个栽培烟草种的5份不同类型烟草与其对应的可能祖先种首先聚为一类。在不同类型普通烟草中扩增到的AFLP共有片段,有97.7%可以在其可能的祖先种中找到。【结论】烟草属植物具有丰富的遗传多样性。栽培烟草进化过程中,其假设的祖先亲本都有一定贡献,其中N.sylvestris对普通烟草的形成贡献最大。

Fluorescent AFLP Analysis of Genetic Diversity and Evolutionary Relatives of Nicotiana Genus

【Objective】 AFLP analysis was used to determine the degree of genetic diversity that exists among cultivated and wild species of Nicotiana representing 3 subgeneras and 5 types. The results of AFLP analysis also provided additional support for the origin and evolution of cultivated species. 【Method】 Thirty- three accessions, including 5 lines representing 4 types of cultivated tobacoo and 28 wild Nicotiana species, were used for fluorescent AFLP analysis and genetic similarity estimation. Twenty-eight wild Nicotiana species and cultivated tobacoo together with their proposed progenitor species were clustered using UPGMA method, respectively. 【Result】 The 10 primers generated 2 423 fragments, of which 2 394 fragments were polymorphic. The genetic similarity coefficient among all materials was varied from 0.021 to 0.860, average 0.269. The 28 wild Nicotiana species were divided into 3 types by a similar coefficient 0.309,which agreed with taxonomy based on morphological characters. Two cultivated species including 5 tobacco cultivars were firstly clustered with their proposed progenitor species, respectively. There were 97.7% common AFLP fragments of different types of N. tabacum could be found in at least one of 3 prorposed progenitor species.【Conclusion】 There was an abundant genetic diversity among Nicotiana germplasms. The progenitor species contributed information to the evolution of the cultivated species, such as the N. tabacum, with the greatest contribution being made by N. sylvestris, the presumed maternal parent.