Ashraf Rimsha, Johansson Eva, Vallenback Pernilla, Steffenson Brian J, Bajgain Prabin, Rahmatov Mahbubjon
Swedish University of Agricultural Sciences, Department of Plant Breeding, P.O. Box 190, SE-234 22 Lomma, Sweden.
Lantmännen Lantbruk, Svalöv, Sweden.
Plant Dis. 2023 Mar;107(3):720-729. doi: 10.1094/PDIS-07-22-1666-RE. Epub 2023 Mar 23.
Wheat stripe rust, caused by f. sp. Eriks. & E. Henn, is the most devastating fungal disease of bread wheat. Here, a wheat-rye multiple disomic substitution line, SLU126 4R (4D), 5R (5D), and 6R (7D), possessing resistance against 25 races of f. sp. , was used and crossed with Chinese Spring to induce homeologous recombination to produce introgressions with a reduced rye chromosome segment. Seedling assays confirmed that the stripe rust resistance from SLU126 was retained over multiple generations. Through genotyping-by-sequencing (GBS) platforms and aligning the putative GBS-single-nucleotide polymorphism (SNPs) to the full-length annotated rye nucleotide-binding leucine-rich repeat (NLR) genes in the parental lines (CS , SLU126, CSA, and SLU820), we identified the physical position of 26, 13, and 9 NLR genes on chromosomes 6R, 4R, and 5R, respectively. The physical positions of 25 NLR genes on chromosome 6R were identified from 568,460,437 bp to 879,958,268 bp in the 6RL chromosome segment. Based on these NLR positions on the 6RL chromosome segment, the three linked SNPs (868,123,650 to 873,285,112 bp) were validated through kompetitive allele-specific PCR (KASP) assays in SLU126 and resistance plants in the family 29-N3-5. Using these KASP markers, we identified a small piece of the rye translocation (i.e., as a possible 6DS.6DL.6RL.6DL) containing the stripe resistance gene, temporary designated , within the 6RL segment. This new stripe rust resistance gene provides an additional asset for wheat improvement to mitigate yield losses caused by stripe rust.
小麦条锈病由小麦隐匿柄锈菌条形柄锈菌致病型引起，是面包小麦最具毁灭性的真菌病害。在此，使用了对25个小麦隐匿柄锈菌致病型生理小种具有抗性的小麦-黑麦多重双体代换系SLU126（4R（4D）、5R（5D）和6R（7D）），并将其与中国春小麦杂交以诱导部分同源重组，从而产生黑麦染色体片段缩短的渗入系。幼苗试验证实，SLU126的条锈病抗性在多代中得以保留。通过简化基因组测序（GBS）平台，并将推定的GBS单核苷酸多态性（SNP）与亲本系（中国春小麦、SLU126、中国春-黑麦附加系和SLU820）中全长注释的黑麦核苷酸结合富含亮氨酸重复序列（NLR）基因进行比对，我们分别在6R、4R和5R染色体上确定了26个、13个和9个NLR基因的物理位置。在6RL染色体区段中，从568,460,437 bp到879,958,268 bp确定了25个NLR基因在6R染色体上的物理位置。基于6RL染色体区段上的这些NLR位置，通过竞争性等位基因特异性PCR（KASP）分析在SLU126和家系29-N3-5中的抗性植株中验证了三个连锁SNP（868,123,650至873,285,112 bp）。使用这些KASP标记，我们在6RL区段内鉴定出一小段含有条锈病抗性基因（暂时命名为）的黑麦易位片段（即可能为6DS.6DL.6RL.6DL）。这个新的条锈病抗性基因为小麦改良提供了一项额外资源，以减轻条锈病造成的产量损失。
