Analysis of phylogenetic relationships of Hordeum (Poaceae) polyploids

多倍体，也就是整个基因组的复制，是植物生物多样性产生的重要机制。在大麦属中，大约一半的分类群是多倍体，大多数是异源多倍体，结合了两个或三个不同亲本种的基因组。对于二倍体类群，已经存在一个很好的系统发育关系假设，而对于多倍体，则几乎没有可用的信息。了解一个类群的系统发育对于进一步分析进化或生态过程是必不可少的。在拟议的项目中，我将通过对这些区域的克隆PCR产物进行测序并使用系统发育分析算法，分析Hordeum中三个单拷贝核标记位点的物种关系。对一些多倍体群体将进行详细的研究，包括序列分析和基因组原位杂交（GISH）。这项工作将有助于更好地了解这一重要的禾草属，建立对禾草或至少在小麦科系统分类中有用的新标记区域，提供多倍体起源的年代测定，并允许进一步分析多倍体发生后或与多倍体相关的基因组和生态变化。

Polyploidy, this means the duplication of entire genomes, is a very important mechanism creating biodiversity in plants. Within the barley genus Hordeum about half of the taxa are polyploids, mostly allopolyploids combining genomes from two or three different parental species. While for the diploid taxa a good hypothesis of phylogenetic relationships already exists, for polyploids few information is available. Knowledge of the phylogeny of a group is indispensable for further analyses of evolutionary or ecological processes. Within the proposed project I will analyze species relationships in Hordeum with three single copy nuclear marker loci by sequencing of cloned PCR products of these regions and using phylogenetic analysis algorithms. For some polyploid groups in-detail studies will be conducted including sequence analysis and genomic in situ hybridization (GISH). The work will result in a better understanding of this important grass genus, will establish new markers regions useful in grass or at least in Triticeae systematics, provide dating of polyploid origins, and will allow further analyses of genomic and ecological changes after or connected with polyploidization.