Mason-Gamer Roberta J
The University of Illinois at Chicago, Department of Biological Sciences, MC 066, Chicago, IL 60607, USA.
Mol Phylogenet Evol. 2008 May;47(2):598-611. doi: 10.1016/j.ympev.2008.02.008. Epub 2008 Mar 10.
The phylogenetic position of hexaploid Elymus repens within the tribe Triticeae (Poaceae) was examined using cloned sequences from the low-copy nuclear genes encoding phosphoenolpyruvate carboxylase (pepC) and beta-amylase. A previous analysis of E. repens using data from the nuclear granule-bound starch synthase I (GBSSI) gene had yielded five phylogenetically distinct gene copies, two more than expected from hexaploidy alone. The three gene trees share three distinct E. repens clades, suggesting that E. repens contains three phylogenetically divergent genomes, contributed by Hordeum, Pseudoroegneria, and an unknown donor. The two additional GBSSI sequences, including one that was apparently derived from outside of the tribe, appear to reflect past introgression of GBSSI sequences into the E. repens genome. On all three trees, the Hordeum-like E. repens sequences are polyphyletic within Hordeum, and the trees are in conflict with regard to the placement of these sequences within Hordeum, highlighting multiple contributions from Hordeum to E. repens.
利用编码磷酸烯醇式丙酮酸羧化酶（pepC）和β-淀粉酶的低拷贝核基因的克隆序列，研究了六倍体偃麦草在小麦族（禾本科）中的系统发育位置。先前使用来自核颗粒结合淀粉合酶I（GBSSI）基因的数据对偃麦草进行的分析产生了五个系统发育上不同的基因拷贝，比仅由六倍体预期的多两个。这三个基因树共有三个不同的偃麦草分支，表明偃麦草包含三个系统发育上不同的基因组，分别由大麦属、拟鹅观草属和一个未知供体贡献。另外两个GBSSI序列，包括一个显然源自该族之外的序列，似乎反映了GBSSI序列过去渗入偃麦草基因组的情况。在所有三个树上，偃麦草中类似大麦属的序列在大麦属内是多系的，并且这些序列在大麦属内的位置上，这些树存在冲突，突出了大麦属对偃麦草的多重贡献。
