Center for Agricultural Resources Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Shijiazhuang, Hebei, 050021, China.
The College of Life Science, University of Chinese Academy of Sciences, Beijing, 101408, China.
Sci Rep. 2018 Jan 11;8(1):475. doi: 10.1038/s41598-017-18827-4.
Wheat powdery mildew is a severe disease affecting yield and quality. Host resistance was proved to be effective and environment-friendly. Wheat line Subtil is an elite germplasm resource resistant to 28 of 30 tested Bgt isolates. Genetic analysis showed that the powdery mildew resistance in Subtil was conferred by a single dominant gene, temporarily designated PmSub. Using bulked segregant analysis, PmSub was mapped to chromosome arm 5DS, and flanked by the markers Bwm16 and Cfd81/Bwm21 at 5.0 and 0.9 cM, respectively. Allelism tests further confirmed PmSub was allelic with documented Pm2 alleles. Then, homologous sequences of Pm2a related sequence was cloned from Subtil and Chinese Spring. It was completely identical to the reported Pm2a sequence, but significantly different from that of Chinese Spring. A marker SWGI067 was developed based on the sequence divergence of homologous sequence in Subtil and Chinese Spring. SWGI067 was closely linked to PmSub, indicating that the gene PmSub itself was different from the cloned Pm2a related sequence. Meanwhile, Subtil produced significantly different reaction pattern compared with other genotypes with Pm genes at or near Pm2 locus. Therefore, PmSub was most likely a new allele of Pm2. PmSub has opportunities for marker-assisted selecting for high-efficiency wheat improvement.
小麦白粉病是一种严重影响产量和品质的病害。已证明寄主抗性是一种有效且环保的方法。小麦品系 Subtil 是一种对 30 个测试的 Bgt 分离物中的 28 个具有抗性的优秀种质资源。遗传分析表明，Subtil 中的白粉病抗性由一个单一的显性基因控制，暂时命名为 PmSub。利用混池分离分析法，将 PmSub 定位到 5DS 染色体臂上，两侧标记分别为 Bwm16 和 Cfd81/Bwm21，距离分别为 5.0 和 0.9cM。等位基因测试进一步证实 PmSub 与已报道的 Pm2 等位基因等位。然后，从 Subtil 和中国春中克隆了与 Pm2a 相关序列的同源序列。它与报道的 Pm2a 序列完全相同，但与中国春的序列有很大的不同。根据 Subtil 和中国春同源序列的序列差异，开发了标记 SWGI067。SWGI067 与 PmSub 紧密连锁，表明基因 PmSub 本身与克隆的 Pm2a 相关序列不同。同时，Subtil 与 Pm2 基因所在或附近的其他基因型相比，表现出明显不同的反应模式。因此，PmSub 很可能是 Pm2 的一个新等位基因。PmSub 为高效小麦改良的标记辅助选择提供了机会。
