Mandák Bohumil, Vít Petr, Krak Karol, Trávníček Pavel, Havrdová Alena, Hadincová Věroslava, Zákravský Petr, Jarolímová Vlasta, Bacles Cecile Fanny Emilie, Douda Jan
Institute of Botany, The Czech Academy of Sciences, Zámek 1, CZ-252 43, Průhonice, Czech Republic; Faculty of Environmental Sciences, Czech University of Life Sciences Prague, Kamýcká 129, Praha 6-Suchdol, CZ-165 21, Czech Republic;
Institute of Botany, The Czech Academy of Sciences, Zámek 1, CZ-252 43, Průhonice, Czech Republic; Faculty of Agriculture, University of South Bohemia, Studentská 13, CZ-370 05, České Budějovice, Czech Republic and.
Ann Bot. 2016 Jan;117(1):107-20. doi: 10.1093/aob/mcv158. Epub 2015 Oct 14.
Polyploidy in plants has been studied extensively. In many groups, two or more cytotypes represent separate biological entities with distinct distributions, histories and ecology. This study examines the distribution and origins of cytotypes of Alnus glutinosa in Europe, North Africa and western Asia.
A combined approach was used involving flow cytometry and microsatellite analysis of 12 loci in 2200 plants from 209 populations combined with species distribution modelling using MIROC and CCSM climatic models, in order to analyse (1) ploidy and genetic variation, (2) the origin of tetraploid A. glutinosa, considering A. incana as a putative parent, and (3) past distributions of the species.
The occurrence of tetraploid populations of A. glutinosa in Europe is determined for the first time. The distribution of tetraploids is far from random, forming two geographically well-delimited clusters located in the Iberian Peninsula and the Dinaric Alps. Based on microsatellite analysis, both tetraploid clusters are probably of autopolyploid origin, with no indication that A. incana was involved in their evolutionary history. A projection of the MIROC distribution model into the Last Glacial Maximum (LGM) showed that (1) populations occurring in the Iberian Peninsula and North Africa were probably interconnected during the LGM and (2) populations occurring in the Dinaric Alps did not exist throughout the last glacial periods, having retreated southwards into lowland areas of the Balkan Peninsula.
Newly discovered tetraploid populations are situated in the putative main glacial refugia, and neither of them was likely to have been involved in the colonization of central and northern Europe after glacial withdrawal. This could mean that neither the Iberian Peninsula nor the western part of the Balkan Peninsula served as effective refugial areas for northward post-glacial expansion of A. glutinosa.
植物多倍体已得到广泛研究。在许多植物类群中，两种或更多的细胞型代表着具有不同分布、历史和生态的独立生物实体。本研究考察欧洲、北非和西亚桤木的细胞型分布及起源。
采用了一种综合方法，涉及对来自209个种群的2200株植物的12个位点进行流式细胞术和微卫星分析，并结合使用MIROC和CCSM气候模型进行物种分布建模，以分析：（1）倍性和遗传变异；（2）四倍体桤木的起源，将灰桤木视为假定亲本；（3）该物种的过去分布。
首次确定了欧洲四倍体桤木种群的存在。四倍体的分布并非随机，形成了位于伊比利亚半岛和迪纳拉阿尔卑斯山的两个地理界限分明的集群。基于微卫星分析，两个四倍体集群可能均起源于同源多倍体，没有迹象表明灰桤木参与了它们的进化历史。将MIROC分布模型投影到末次盛冰期（LGM）显示：（1）伊比利亚半岛和北非的种群在末次盛冰期可能相互连接；（2）迪纳拉阿尔卑斯山的种群在整个末次冰期并不存在，已向南退缩至巴尔干半岛的低地地区。
新发现的四倍体种群位于假定的主要冰期避难所，且它们都不太可能参与冰期消退后中欧和北欧的殖民化。这可能意味着伊比利亚半岛和巴尔干半岛西部都没有作为桤木冰期后向北扩张的有效避难区。
