Arid Land Research Center, Tottori University, Tottori, Japan.
United Graduate School of Agricultural Sciences, Tottori University, Tottori, Japan.
Sci Rep. 2018 Oct 31;8(1):16117. doi: 10.1038/s41598-018-34545-x.
Developing wheat-alien chromosome introgression lines to improve bread wheat's resistance to stresses, such as drought, salinity stress and diseases, requires reliable markers to identify and characterize the alien chromatins. Leymus mollis is a wild relative of bread wheat resistant to salinity and economically important diseases of wheat, but its genome sequence and cytological markers are not available. We devised a molecular marker-assisted strategy for L. mollis chromosome identification and applied it to produce 10 wheat-L. mollis chromosome addition lines. Using 47 L. racemosus genome polymorphic PCR markers and DArTseq genotyping, we distinguished the L. mollis chromosomes and differentiated disomic and monosomic lines by progeny test. DArTseq genotyping generated 14,530 L. mollis SNP markers and the chromosome-specific SNP markers were used to determine the homoeologous groups of L. mollis chromosomes in the addition lines. To validate the marker-based results, genomic in situ hybridization was applied to confirm the presence and cytological status of L. mollis chromosomes in the lines. This study demonstrates that adequate molecular markers allow the production and characterization of wheat-alien addition lines without in situ hybridization, which saves considerable time and effort.
为了提高小麦对干旱、盐胁迫和疾病等胁迫的抗性，需要可靠的标记来鉴定和描述外源染色质。赖草是一种野生近缘种，具有耐盐性和重要的小麦经济病害抗性，但它的基因组序列和细胞学标记尚未可知。我们设计了一种赖草染色体鉴定的分子标记辅助策略，并应用该策略生产了 10 条小麦-赖草染色体添加系。利用 47 个赖草基因组多态性 PCR 标记和 DArTseq 基因分型，我们通过后代测试区分了赖草染色体，并通过分离出二体和单体系来区分。DArTseq 基因分型产生了 14530 个赖草 SNP 标记，染色体特异性 SNP 标记用于确定添加系中赖草染色体的同源群。为了验证基于标记的结果，我们应用基因组原位杂交来确认添加系中赖草染色体的存在和细胞学状态。本研究表明，充分的分子标记允许在不进行原位杂交的情况下生产和鉴定小麦外源添加系，这节省了相当多的时间和精力。
