Introgression of chromatin from Secale species into common wheat has for decades been a successful strategy for controlling the wheat diseases. The wild Secale species, Secale africanum Stapf., is a valuable source for resistance to foliar disease of wheat. A wheat-S. africanum chromosome 6Rafr substitution line displayed resistance to both powdery mildew and stripe rust at the adult-plant stage. Wheat-S. africanum chromosome 6Rafr deletion and translocation lines were produced and identified by sequential non-denaturing fluorescence in situ hybridization (ND-FISH) using multiple Oligo-based probes. Different ND-FISH patterns were observed between S. cereale 6R and S. africanum 6Rafr. With reference to the physical map of the draft genome sequence of rye inbred line Lo7, a comprehensive PCR marker analysis indicated that insertions and deletions had occurred by random exchange between chromosomes 6R and 6Rafr. A survey of the wheat- S. africanum 6Rafr lines for disease resistance indicated that a powdery mildew resistance gene(s) was present on the long arm of 6Rafr at FL0.85–1.00, and that a stripe rust resistance gene(s) was located in the terminal region of 6RafrS at FL0.95–1.00. The wheat-S. africanum 6Rafr introgression lines also displayed superior agronomic traits, indicating that the chromosome 6Rafr may have little linkage drag in the wheat background. The combination of molecular and cytogenetic methods allowed to precisely identify the chromosome rearrangements in wheat- S. africanum 6Rafr substitution, deletion and translocation lines, and compare the structural difference between chromosomes 6R and 6Rafr. The wheat- S. africanum 6Rafr lines containing gene(s) for powdery mildew and stripe rust resistance could be used as novel germplasm for wheat breeding by chromosome engineering.

中文翻译：

---

小麦中Secale Africanum 6R ^afr染色体的分子解剖使得能够定位抗白粉病和条锈病的基因

数十年来，染色质从Secale物种渗入普通小麦一直是控制小麦疾病的成功策略。野生的Secale种，Secale africanum Stapf。，是抵抗小麦叶片病的重要来源。小麦S。Africanum染色体6Rafr替代品系在成株期对白粉病和条锈病均表现出抗性。小麦-S。使用多个基于Oligo的探针，通过连续非变性荧光原位杂交（ND-FISH）产生并鉴定了africanum染色体6Rafr缺失和易位系。在谷物链霉菌6R和非洲链霉菌6Rafr之间观察到不同的ND-FISH模式。参照黑麦近交系Lo7基因组序列草图的物理图谱，全面的PCR标记分析表明，插入和缺失是通过6R和6Rafr染色体之间的随机交换发生的。小麦-非洲链球菌6Rafr品系的抗病性调查表明，在6Rafr的长臂上FL0.85–1.00处存在白粉病抗性基因，条带锈病抗性基因为位于6RafrS的末端区域，位于FL0.95–1.00。小麦-S。非洲菊6Rafr基因渗入系也显示出优良的农艺性状，表明6Rafr染色体在小麦背景中可能几乎没有连锁阻力。分子和细胞遗传学方法的结合，可以精确地鉴定小麦-非洲车手6Rafr替代，缺失和易位系的染色体重排，并比较6R和6Rafr染色体的结构差异。含有抗白粉病和条纹锈病抗性基因的小麦-非洲链霉菌6Rafr品系可用作通过染色体工程育种的新型小麦种质。