Storme V, Vanden Broeck A, Ivens B, Halfmaerten D, Van Slycken J, Castiglione S, Grassi F, Fossati T, Cottrell J E, Tabbener H E, Lefèvre F, Saintagne C, Fluch S, Krystufek V, Burg K, Bordács S, Borovics A, Gebhardt K, Vornam B, Pohl A, Alba N, Agúndez D, Maestro C, Notivol E, Bovenschen J, van Dam B C, van der Schoot J, Vosman B, Boerjan W, Smulders M J M
Department of Plant Systems Biology, Flanders Interuniversity Institute for Biotechnology (VIB), Ghent University, Technologiepark 927, 9052, Gent, Belgium.
Theor Appl Genet. 2004 Apr;108(6):969-81. doi: 10.1007/s00122-003-1523-6. Epub 2003 Dec 13.
Populus nigra L. is a pioneer tree species of riparian ecosystems that is threatened with extinction because of the loss of its natural habitat. To evaluate the existing genetic diversity of P. nigra within ex-situ collections, we analyzed 675 P. nigra L. accessions from nine European gene banks with three amplified fragment length polymorphism (AFLP) and five microsatellite [or simple sequence repeat (SSR)] primer combinations, and 11 isozyme systems. With isozyme analysis, hybrids could be detected, and only 3% were found in the gene bank collection. AFLP and SSR analyses revealed effectively that 26% of the accessions were duplicated and that the level of clonal duplication varied from 0% in the French gene bank collection up to 78% in the Belgian gene bank collection. SSR analysis was preferred because AFLP was technically more demanding and more prone to scoring errors. To assess the genetic diversity, we grouped material from the gene banks according to topography of the location from which the accessions were originally collected (river system or regions separated by mountains). Genetic diversity was expressed in terms of the following parameters: percentage of polymorphic loci, observed and effective number of alleles, and Nei's expected heterozygosity or gene diversity (for AFLP). Genetic diversity varied from region to region and depended, to some extent, on the marker system used. The most unique alleles were identified in the Danube region (Austria), the Rhône region (France), Italy, the Rijn region (The Netherlands), and the Ebro region (Spain). In general, the diversity was largest in the material collected from the regions in Southern Europe. Dendrograms and principal component analysis resulted in a clustering according to topography. Material from the same river systems, but from different countries, clustered together. The genetic differentiation among the regions (F(st)/G(st)) was moderate.
黑杨是河岸生态系统的先锋树种，因其自然栖息地丧失而面临灭绝威胁。为评估黑杨迁地保护群体内现有的遗传多样性，我们使用3种扩增片段长度多态性（AFLP）和5种微卫星[或简单序列重复（SSR）]引物组合以及11个同工酶系统，分析了来自9个欧洲基因库的675份黑杨样本。通过同工酶分析能够检测到杂种，且在基因库样本中仅发现3%为杂种。AFLP和SSR分析有效揭示出26%的样本存在重复，克隆重复水平在法国基因库样本中为0%，在比利时基因库样本中高达78%。由于AFLP技术要求更高且更容易出现评分错误，因此更倾向于使用SSR分析。为评估遗传多样性，我们根据样本最初采集地点的地形（河流系统或被山脉分隔的区域）对基因库中的材料进行分组。遗传多样性通过以下参数表示：多态位点百分比、观察到的和有效的等位基因数，以及Nei期望杂合度或基因多样性（用于AFLP）。遗传多样性因地区而异，在一定程度上取决于所使用的标记系统。在多瑙河地区（奥地利）、罗纳河地区（法国）、意大利、莱茵河地区（荷兰）和埃布罗河地区（西班牙）鉴定出了最独特的等位基因。总体而言，来自南欧地区的材料多样性最大。聚类图和主成分分析结果显示根据地形进行了聚类。来自相同河流系统但不同国家的材料聚集在一起。各地区之间的遗传分化（F(st)/G(st)）适中。
