Wheatgrass (Agropyron sp.) is a potential source of beneficial traits for wheat improvement. Among them, crested wheatgrass [A. cristatum (L.) Gaertn.] comprises a complex of diploid, tetraploid, and hexaploid forms with the basic genome P, with some accessions carrying supernumerary B chromosomes (Bs). In this work, we applied flow cytometry to dissect the complex genome of crested wheatgrass into individual chromosomes to facilitate its analysis. Flow karyotypes obtained after the analysis of 4ʹ,6‐diamidino‐2‐phenylindole (DAPI)‐stained mitotic chromosomes of diploid and tetraploid accessions consisted of three peaks, each corresponding to a group of two or three chromosomes. To improve the resolution, bivariate flow karyotyping after fluorescent labeling of chromosomes with fluorescein isothiocyanate (FITC)‐conjugated probe (GAA)₇ microsatellite was applied and allowed discrimination and sorting of P genome chromosomes from wheat–crested wheatgrass addition lines. Chromosomes 1P–6P and seven telomeric chromosomes could be sorted at purities ranging from 81.7 to 98.2% in disomics and from 44.8 to 87.3% in telosomics. Chromosome 7P was sorted at purities reaching 50.0 and 39.5% in diploid and tetraploid crested wheatgrass, respectively. In addition to the whole complement chromosomes (A), Bs could be easily discriminated and sorted from a diploid accession at 95.4% purity. The sorted chromosomes will streamline genome analysis of crested wheatgrass, facilitating gene cloning and development of molecular tools to support alien introgression into wheat.

中文翻译：

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通过染色体分流解剖解剖有冠的小麦草的复杂基因组。

小麦草（Agropyron sp。）是小麦改良有益特性的潜在来源。其中，凤头小麦草[A．变种（C. cristatum（L.）Gaertn。]包含二倍体，四倍体和六倍体形式与基本基因组P的复合物，其中一些种质携带超数B染色体（Bs）。在这项工作中，我们应用流式细胞仪将有冠小麦草的复杂基因组分解为单个染色体，以方便对其进行分析。分析4ʹ，6-二mid基-2-苯基吲哚（DAPI）染色的二倍体和四倍体种的有丝分裂染色体后获得的流型核型由三个峰组成，每个峰对应一组两个或三个染色体。为了提高分辨率，在异硫氰酸荧光素（FITC）偶联探针（GAA）荧光标记染色体后进行双变量核型分析_{应用了7个}微卫星，可以区分和鉴定小麦有穗小麦草附加系中的P基因组染色体。1P-6P染色体和七个端粒染色体的分类纯度在二体组学中为81.7％至98.2％，在端粒体中为44.8％至87.3％。在二倍体和四倍体冠状小麦草中，7P染色体的纯度分别达到50.0和39.5％。除了完整的补体染色体（A），Bs还可以容易地与95.4％纯度的二倍体种区分和分类。排序后的染色体将简化有冠小麦草的基因组分析，促进基因克隆和分子工具的开发，以支持外来基因渗入小麦。