Development and identification of an elite wheat-Hordeum californicum T6HcS/6BL translocation line ND646 containing several desirable traits

Abstract Hordeum californicum (H. californicum, 2n=2X=14, HcHc), one of the wild relatives of wheat (Triticum aestivum L.), harbors many desirable genes and is a potential genetic resource for wheat improvement. In this study, an elite line ND646 was selected from a BC4F5 population, which was developed using 60Co-γ irradiated wheat-H. californicum disomic addition line WJ28-1 (DA6Hc) as the donor parent and Ningchun 4 as the recurrent parent. ND646 was identified as a novel wheat-H. californicum 6HcS/6BL translocation line using genomic in situ hybridization (GISH), fluorescence in situ hybridization (FISH), and H. californicum-specific expressed sequence tag (EST) markers. Further evaluation revealed that ND646 had excellent performance in several traits, such as a higher sedimentation value (SV), higher water absorption rate (WAR), and higher hardness index (HI). More importantly, it had more kernels per spike (KPS), a higher grain yields (GY), and good resistance to powdery mildew, leaf rust, and 2,4-D butylate (2,4-D). Its excellent phenotypic performance laid the foundation for further investigation of its genetic architecture and makes ND646 a useful germplasm resource for wheat breeding.

摘要：加州大麦（Hordeum californicum，简称H. californicum，染色体组型2n=2X=14，基因组组成为HcHc）是普通小麦（Triticum aestivum L.）的野生近缘物种之一，携带有诸多优良基因，是小麦遗传改良的潜在种质资源。本研究以经60Co-γ射线辐照的小麦-加州大麦二体附加系WJ28-1（DA6Hc）为供体亲本、宁春4号为轮回亲本，构建回交4代自交5代（BC4F5）群体，并从中筛选得到优良品系ND646。通过基因组原位杂交（genomic in situ hybridization, GISH）、荧光原位杂交（fluorescence in situ hybridization, FISH）以及加州大麦特异性表达序列标签（expressed sequence tag, EST）标记鉴定，确认ND646为新型小麦-加州大麦6HcS/6BL易位系。进一步的性状评价结果显示，ND646在多个性状上表现优异：沉降值（sedimentation value, SV）、吸水率（water absorption rate, WAR）及硬度指数（hardness index, HI）均较高；更重要的是，其每穗粒数（kernels per spike, KPS）更多、籽粒产量（grain yields, GY）更高，且对白粉病（powdery mildew）、叶锈病（leaf rust）以及2,4-滴丁酯（2,4-D butylate）均具有良好抗性。该材料优异的表型性状为其遗传结构的深入解析奠定了基础，同时也使ND646成为小麦育种中极具应用价值的种质资源。