Center for Informational Biology, School of Life Science and Technology, University of Electronic and Technology of China, Chengdu, 611731, Sichuan, China.
Crop Research Institute, Sichuan Academy of Agricultural Sciences, Chengdu, 610066, Sichuan, China.
BMC Plant Biol. 2020 Mar 31;20(1):134. doi: 10.1186/s12870-020-02351-1.
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 6R substitution line displayed resistance to both powdery mildew and stripe rust at the adult-plant stage.
Wheat-S. africanum chromosome 6R 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 6R. 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 6R. A survey of the wheat- S. africanum 6R lines for disease resistance indicated that a powdery mildew resistance gene(s) was present on the long arm of 6R at FL0.85-1.00, and that a stripe rust resistance gene(s) was located in the terminal region of 6RS at FL0.95-1.00. The wheat-S. africanum 6R introgression lines also displayed superior agronomic traits, indicating that the chromosome 6R 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 6R substitution, deletion and translocation lines, and compare the structural difference between chromosomes 6R and 6R. The wheat- S. africanum 6R lines containing gene(s) for powdery mildew and stripe rust resistance could be used as novel germplasm for wheat breeding by chromosome engineering.
将黑麦属物种的染色质导入普通小麦中，几十年来一直是控制小麦病害的成功策略。野生黑麦属物种，Secale africanum Stapf.，是一种控制小麦叶部病害的宝贵资源。一个小麦-黑麦属非洲种 6R 代换系在成株期表现出对白粉病和条锈病的抗性。
通过使用多个基于寡核苷酸的探针进行顺序非变性荧光原位杂交（ND-FISH），产生并鉴定了小麦-黑麦属非洲种 6R 缺失和易位系。在 S. cereale 6R 和 S. africanum 6R 之间观察到不同的 ND-FISH 模式。参照黑麦近等基因系 Lo7 基因组草图序列的物理图谱，全面的 PCR 标记分析表明，染色体 6R 之间发生了随机交换的插入和缺失。对小麦-黑麦属非洲种 6R 系的抗病性调查表明，在 6R 的长臂 FL0.85-1.00 上存在一个或多个抗白粉病基因，在 6RS 的末端区域 FL0.95-1.00 上存在一个或多个抗条锈病基因。小麦-黑麦属非洲种 6R 导入系还表现出优良的农艺性状，表明该染色体在小麦背景下可能很少有连锁累赘。
分子和细胞遗传学方法的结合可以精确地鉴定小麦-黑麦属非洲种 6R 代换、缺失和易位系中的染色体重排，并比较 6R 和 6R 之间的结构差异。含有白粉病和条锈病抗性基因的小麦-黑麦属非洲种 6R 系可以作为通过染色体工程进行小麦育种的新型种质资源。
