State Key Laboratory of Crop Stress Adaptation and Improvement, College of Agriculture, Henan University, Kaifeng, 475004, Henan, China.
Key Laboratory of Wheat Biology and Genetic Improvement on Southwestern China, Crop Research Institute, Sichuan Academy of Agricultural Sciences, Chengdu, 610066, Sichuan, China.
Theor Appl Genet. 2022 May;135(5):1657-1669. doi: 10.1007/s00122-022-04061-8. Epub 2022 Mar 2.
The powdery mildew resistance gene Pm58 was traced to a 141.3-kb interval with the co-segregating marker Xkasp68500 in wheat breeding. Pm58 is a powdery mildew resistance gene identified in Aegilops tauschii accession TA1662 and effective in a common wheat background. To finely map Pm58, an F population of 676 plants derived from the cross T093 × TA1662 was used for recombinant screening. We obtained 13 recombinants that occurred between the flanking markers Xhnu670 and Xhnu186. Genotyping and phenotyping these recombinant F families delimited Pm58 to a 0.22-cM interval (Xsts20220-Xkasp61553) on chromosome arm 2DS. The region carrying the Pm58 locus was approximately 141.3-kb, which contained eight annotated genes according to the reference genome sequence of Ae. tauschii AL8/78. Haplotype analysis of 178 Ae. tauschii accessions using the candidate gene-specific markers identified a disease resistance gene AET2Gv20068500 as a candidate for Pm58. Comparative mapping of the Pm58-containing interval revealed two presence/absence variations (PAVs) between AL8/78 and common wheat Chinese Spring. PAV-1 resides in the 3'-end of AET2Gv20068500. The majority of 158 common wheat cultivars (84.8%) displayed the absence of a 14.1-kb fragment in the PAV-1 region, which was confirmed by aligning the targeted genome sequences of the other sequenced Ae. tauschii accessions and common wheat cultivars. A co-segregating marker Xkasp68500 developed from AET2Gv20068500 can distinguish TA1662 from all randomly selected common wheat cultivars and will be instrumental for tracking Pm58 in breeding programs.
小麦育种中，白粉病抗性基因 Pm58 被追溯到一个 141.3kb 的区间，与共分离标记 Xkasp68500 相关。Pm58 是在 Ae. tauschii accession TA1662 中鉴定的白粉病抗性基因，在普通小麦背景下有效。为了精细定位 Pm58，利用 T093 × TA1662 杂交产生的 676 株 F1 群体进行重组筛选。我们获得了 13 个位于侧翼标记 Xhnu670 和 Xhnu186 之间的重组体。对这些重组 F2 家系进行基因型和表型分析，将 Pm58 限定在 2DS 染色体臂上的 0.22cM 区间（Xsts20220-Xkasp61553）。携带 Pm58 基因座的区域约为 141.3kb，根据 Ae. tauschii AL8/78 的参考基因组序列，包含 8 个注释基因。利用候选基因特异性标记对 178 个 Ae. tauschii 材料进行单倍型分析，鉴定出一个抗病基因 AET2Gv20068500 作为 Pm58 的候选基因。含 Pm58 区间的比较作图显示，AL8/78 与普通小麦中国春之间存在两个存在/缺失变异（PAVs）。PAV-1 位于 AET2Gv20068500 的 3'-端。158 个普通小麦品种（84.8%）的大多数在 PAV-1 区域缺失 14.1kb 片段，这通过对齐其他测序的 Ae. tauschii 材料和普通小麦品种的目标基因组序列得到了证实。从 AET2Gv20068500 中开发的共分离标记 Xkasp68500 可以区分 TA1662 与所有随机选择的普通小麦品种，将有助于在育种计划中追踪 Pm58。
