抗条锈病的小麦-非洲黑麦异代换系的分子细胞学鉴定  

Molecular Cytogenetic Characterization of a Triticum durum-Secale africanum Substitution Line for Resistance to Sripe Rust(Puccinia striiformis Eriks.f.sp.tritici)

作　　者：雷孟平[1] 李光蓉[1] 刘成[1] 杨足君[1] 

机构地区：[1]电子科技大学生命科学与技术学院,成都610054

出　　处：《农业生物技术学报》2013年第3期263-271,共9页Journal of Agricultural Biotechnology

基　　金：国家自然科学基金(No.31171542和31101143);中国博士后基金(No.Y02006023601261)

摘　　要：黑麦属(Secale)物种是改良小麦条锈病抗性的优良供体,为发掘和利用黑麦属野生种非洲黑麦(S.africanum)所携带的优异抗小麦条锈病基因,本研究在硬粒小麦(Triticum durum)-非洲黑麦双二倍体(基因组为AABBRaRa)和小麦(T.aestivum)杂交的高代材料中发现了一个免疫条锈病的株系HH41。HH41的体细胞染色体数目为2n=42。用小麦D基因组特异重复序列pAs1和秦岭黑麦(S.cereale)基因组总DNA作为探针的顺序原位杂交分析表明,HH41中一对小麦6D染色体被一对非洲黑麦6Ra染色体所代换。利用开发的基于表达序列标签的6R/6Ra特异分子标记也证实了HH41缺少6D特征带,具有6Ra特征带,是6Ra(6D)代换系。条锈菌生理小种(Puccinia striiformis Eriks.f.sp.tritici)接种鉴定结果表明其抗条锈病性源自6Ra染色体。本研究还综合利用分子细胞学证据将来自非洲黑麦的6Ra染色体与栽培黑麦的6R染色体的多态性进行了比较,证实了6Ra(6D)代换系HH41是一种具有古老野生黑麦优异抗性的特殊珍贵材料,是创造异易位系、实现外源基因转移和改良小麦的重要资源。Species in genus Secale have provided novel rust resistance genes to protect wheat from this fungal disease. In order to transfer new stripe rust resistance gene （s） from wild Secale species, Secale africanum, we obtained a line HH41 from the advanced generation of Triticum dururn-Secale africanum amphiploid （AABBRaR9 crossed with wheat （T. aest＆um）. Line HH41 was immune to stripe rust isolates from China, and had 42 chromosomes. Fluorescence in situ hybridization （FISH） using D-chromosome specific probe pAsl and sequential genomic in situ hybridization （GISH） analysis using S. cereale cv. Qinglingheimai （QH） genomic DNA as probe demonstrated that a pair of wheat chromosomes 6D were absent, but a pair of S. africanum chromosomes presented in HH41. Expressed sequence tags based molecular markers also confirmed that HH41 lost 6D specific bands and amplified 6R~ specific bands, indicating that HH41 was a 6R＂ （6D） substitution line.GISH analysis using genomic DNA ofS. cereale cv. Qinglingheimai（QH） as a probe showed that hybridization signal covered along the chromosomes 6Ra except the telomere region of the short arm. However, the whole 6Ra chromosomes possessed hybridization signal if using genomic DNA of S. africanum for GISH analysis. FISH using Secale telomere or subtelomere tandem repetitive sequences pSc200 as a probe, no hybridization signal was detected on HH41. However, apparent signal was observed on chromosomes 6R from CS-S. cereale cv, Imperial disomic addition lines with strong signal on the telomere of the short arms were also scattered signal on the subtelomere of the long arms. It was revealed that chromosomes 6Ra of S. africanum were different from the S. cereale chromosomes 6R, especially on the telomere regions, with lost or reduced telomere or subtelomere repetitive sequences. Nine of sixteen 6R/6R＂ specific markers developed by our study represented polymorphic amplification on chromosomes 6Ra of S. africanum distinct from chromosomes 6R of S. cereale, further

关 键 词：原位杂交 分子标记 6Ra(6D)代换系 抗条锈病 非洲黑麦 

分 类 号：S435.121.4[农业科学—农业昆虫与害虫防治]