Physical Mapping of Stem Rust Resistance Gene Sr52 from Dasypyrum villosum Based on ph1b-Induced Homoeologous Recombination
Physical Mapping of Stem Rust Resistance Gene Sr52 from Dasypyrum villosum Based on ph1b-Induced Homoeologous Recombination
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基于ph1b诱导同源重组的绒毛茎锈病基因Sr52物理定位
DOI：
10.3390/ijms20194887
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发表时间：
2019-10-01
影响因子：
5.6
通讯作者：
Li, Tianya
中科院分区：
文献类型：
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作者：
Li, Huanhuan;Dong, Zhenjie;Li, Tianya
小麦秆锈病是由禾柄锈菌（Puccinia graminis f.）番茄叶霉病（Pgt）是世纪世界范围内的一种严重病害。随着Ug 99小种的出现，它们对小麦品种和高级品系中部署的大多数茎锈病抗性基因都是有毒的，茎锈病再次成为威胁全球小麦生产的疾病。Sr 52基因定位于簇毛麦6V#3的长臂上，是少数几个对Ug 99小种有效的基因之一。本研究以小麦D.将迄今为止唯一一个携带Sr 52的簇毛麦罗伯逊易位系T6 AS·6V#3L与CS ph 1b突变体杂交，以诱导具有定位于Sr 52的缩短的6V#3L染色体片段的重组体。六个独立的纯合重组体具有不同的片段大小和断点，其特征在于使用原位杂交和分子标记分析。抗秆锈性鉴定结果表明，只有3个末端重组体（1381、1380和1392）分别含有8%、22%和30%的6V#3L远端片段，对秆锈具有抗性。因此，基因Sr 52被定位到6V#3L bin FL 0.92-1.00中。此外，在6V#3L的Sr 52定位区间内的3个分子标记被证实是筛选Sr 52渗入普通小麦的诊断标记。新开发的含Sr 52的小片段易位系和已鉴定的与Sr 52紧密连锁的分子标记将对小麦病害育种具有重要价值。
Wheat stem rust caused by Puccinia graminis f. sp. tritici (Pgt) had been a devastating foliar disease worldwide during the 20th century. With the emergence of Ug99 races, which are virulent to most stem rust resistance genes deployed in wheat varieties and advanced lines, stem rust has once again become a disease threatening global wheat production. Sr52, derived from Dasypyrum villosum and mapped to the long arm of 6V#3, is one of the few effective genes against Ug99 races. In this study, the wheat–D. villosum Robertsonian translocation T6AS·6V#3L, the only stock carrying Sr52 released to experimental and breeding programs so far, was crossed with a CS ph1b mutant to induce recombinants with shortened 6V#3L chromosome segments locating Sr52. Six independent homozygous recombinants with different segment sizes and breakpoints were developed and characterized using in situ hybridization and molecular markers analyses. Stem rust resistance evaluation showed that only three terminal recombinants (1381, 1380, and 1392) containing 8%, 22%, and 30% of the distal segment of 6V#3L, respectively, were resistant to stem rust. Thus, the gene Sr52 was mapped into 6V#3L bin FL 0.92–1.00. In addition, three molecular markers in the Sr52-located interval of 6V#3L were confirmed to be diagnostic markers for selection of Sr52 introgressed into common wheat. The newly developed small segment translocation lines with Sr52 and the identified molecular markers closely linked to Sr52 will be valuable for wheat disease breeding.