利用普通小麦-冰草异附加系5113创制携带高产、抗病等优异性状新种质

Agropyron cristatum (L.) Gaertn. (2n = 4x = 28, genomes PPPP), is a wheat wild relative, which carries many desirable traits, making it a potentially vital gene pool for wheat improvement. The wheat-Agropyron cristatum disomic addition line 5113 harbored some desirable genes, such as reducing plant height, longer spike length, multiple tillers, the characteristics of increased numbers of florets and kernels per spike, and resistance to powdery mildew and leaf rust. It is an urgent problem to be solved using those excellent genes from 5113 for wheat improvement. In this project, the wheat-Agropyron cristatum disomic addition line 5113 will be used as materials to produce wheat-Agropyron cristatum 6P deletion and translocation lines induced by 60Co-γ irradiation. Genomic in situ hybridization (GISH) and Fluorescence in situ hybridization (FISH) will be applied to identify the 6P chromosome segments in deletion and translocation lines. The 6P chromosome molecular marker bin-map will be constructed by 6P chromosome specific molecular markers. In addition, according to the agronomic performance of wheat-Agropyron cristatum translocation lines and the result of molecular marker identification, combined with 6P chromosome molecular marker bin-map, those excellent genes from 5113 will be located on different 6P chromosome regions. Further more, The physical map of Agropyron cristatum 6P chromosome will supply enough molecular markers in quick and accurate for gene discovery as well as 6P chromosome structural and functional analysis. Various types of wheat Agropyron cristatum 6P translocation lines, which contain excellent genes, will provide novel genetic materials for wheat improvement.

冰草（Agropyron cristatum (L.) Gaertn.）是小麦野生近缘物种，具有多个优异性状基因，是小麦遗传改良的重要基因源。普通小麦-冰草6P二体附加系5113中含有矮秆、大穗、多花多粒、多分蘖、对白粉病和叶锈病免疫等多个优异基因，利用5113中优异基因对小麦进行遗传育种改良具有重要意义。本项目以5113为材料，通过电离辐照、回交、自交等方法创制含有不同大小外源染色体片段的小麦-冰草缺失系和易位系。利用细胞学观察和荧光原位杂交对缺失系和易位系中外源染色体片段进行鉴定，结合开发的6P染色体特异分子标记，建立6P染色体分子标记图谱。根据不同外源染色体片段大小的缺失系和易位系携带的优异基因结合6P染色体分子标记图谱把小麦-冰草异源附加系5113优异基因定位在6P染色体相应区段上。进一步鉴定出含有优异性状基因的小麦-冰草异源纯合易位系，为小麦遗传育种改良提供新种质。

【背景】作为重要的小麦野生近缘物种之一，冰草（Agropyron cristatum (L.) Gaertn.）具有多个优异性状基因可以为小麦遗传改良提供重要基因源。而小麦异源附加系是进一步研究和利用外源优异基因的桥梁工具，5113是我们前期鉴定到的一个小麦-冰草6P二体附加系，含有多个优异基因，如矮秆、大穗、多花多粒、多分蘖、对白粉病和叶锈病免疫等。利用5113中优异基因对小麦进行遗传育种改良具有重要意义。【主要研究内容】本项目以小麦-冰草6P附加系5113为材料，主要开展以下几个方面的研究：（1）创制含有不同大小外源染色体片段的小麦-冰草易位系和缺失系，并对易位系中携带的优异性状进行鉴定；（2）利用细胞学观察和荧光原位杂交（Fluorescence in situ hybridization, FISH）结合6P染色体特异分子标记对缺失系和易位系中外源染色体片段进行鉴定，根据易位系和缺失系中外源染色体片段的大小和数量，创制6P染色体Bin图谱，并把小麦-冰草异源附加系5113优异基因定位在6P染色体相应区段上；（3）获得可以追踪易位系中外源染色体片段的分子标记，为利用易位系对小麦进行遗传育种改良奠定基础。【重要结果及关键数据】（1）创制出6个携带涉及产量、抗病等多个优异性状的小麦-冰草新种质，并获得1个能够稳定遗传的携带有白粉病抗性基因的纯合易位系，为小麦育种改良提供新的种质资源；（2）获得可以追踪6P染色体不同区段的特异分子标记，为小麦遗传育种改良提供新种质；（3）依托该基因发表期刊论文2篇，培养本科生3名，研究生2名。【科学意义】从小麦野生近缘属物种中挖掘优异基因对拓宽小麦遗传资源、丰富小麦品种的遗传多样性和促成新品种的育成具有重要意义。冰草作为重要的小麦野生近缘属植物，能够为小麦遗传育种改良提供丰富的优异基因。