Sea barley Hordeum marinum is an important germplasm resource. However, the origin of this tetraploid H. marinum subsp. gussoneanum is still unclear, which has caused great perplexity to the exploration and utilization of germplasm resources. We used two single-copy nuclear genes, thioredoxin-like gene (TRX) and waxy1 gene encoding granule-bound starch synthase (WAXY1) to analyze 41 accessions of Hordeum marinum. The phylogenies of different genes told different story of evolution of tetraploids of H. marinum subsp. gussoneanum. The phylogenetic trees showed that two distinct copies of sequences from both genes were detected for some accessions of the tetraploids of H. marinum subsp. gussoneanum, and diploid marinum might also contribute to the origin and evolution of the tetraploid gussoneanum. Our findings suggested that tetraploid more likely originated from the diploids of H. marinum subsp. gussoneanum and another ancestor that might be an extinct unknown diploid species. Homogenization of gene in tetraploids also occurred after polyploidization as both TRX and WAXY1 sequences in some accessions of tetraploid H. marinum subsp. gussoneanum cannot be distinguished, indicating the complicated evolution of this tetraploid.

bar米大麦是重要的种质资源。然而，这种四倍体H的起源。马里纳姆亚种 葛根尚不清楚，这给种质资源的勘探和利用造成了极大的困惑。我们使用两个单拷贝核基因，硫氧还蛋白样基因（TRX）和编码颗粒结合淀粉合成酶（waxy1基因WAXY1）来分析41个种质大麦海鱼。不同基因的系统发育告诉了H四倍体进化的不同故事。马里纳姆亚种 古森。系统进化树显示，对于H的四倍体，一些基因的两个基因序列的拷贝明显不同。马里纳姆亚种 gussoneanum和二倍体marinum也可能有助于四倍体gussoneanum的起源和进化。我们的发现表明四倍体更可能起源于H的二倍体。马里纳姆亚种 gussoneanum和另一个祖先，可能是已灭绝的未知二倍体物种。多倍体化后，TRX和WAXY1也发生了四倍体基因的均质化在四倍体的一些种质序列ħ。马里纳姆亚种 gussoneanum无法区分，表明该四倍体的复杂进化。