Development, identifcation, and utilization of wheat–tetraploid Thinopyrum elongatum 4EL translocation lines resistant to stripe rust

https://doi.org/10.1007/s00122-023-04525-5

Theoretical and Applied Genetics (2024) 137:17

Biran Gong, Linfeng Chen, Hao Zhang, Wei Zhu, Lili Xu, Yiran Cheng, Yi Wang, Jian Zeng, Xing Fan, Lina Sha, Haiqin Zhang, Guoyue Chen, Yonghong Zhou, Houyang Kang, Dandan Wu

Abstract

Tetraploid Thinopyrum elongatum is a valuable genetic resource for improving the resistance of wheat to diseases such as stripe rust, powdery mildew, and Fusarium head blight. We previously reported that chromosome 4E of the 4E (4D) substitution line carries all-stage stripe rust resistance genes. To optimize the utility of these genes in wheat breeding programs, we developed translocation lines by inducing chromosomal structural changes through 60Co-γ irradiation and developing monosomic substitution lines. In total, 53 plants with diferent 4E chromosomal structural changes were identifed. Three homozygous translocation lines (T4DS·4EL, T5AL·4EL, and T3BL·4EL) and an addition translocation line (T5DS·4EL) were confrmed by the genomic in situ hybridization (GISH), fuorescence in situ hybridization (FISH), FISH-painting, and wheat 55 K SNP array analyses. These four translocation lines, which contained chromosome arm 4EL, exhibited high stripe rust resistance. Thus, a resistance gene (tentatively named Yr4EL) was localized to the chromosome arm 4EL of tetraploid Th. elongatum. For the application of marker-assisted selection (MAS), 32 simple sequence repeat (SSR) markers were developed, showing specifc amplifcation on the chromosome arm 4EL and co-segregation with Yr4EL. Furthermore, the 4DS·4EL line could be selected as a good pre-breeding line that better agronomic traits than other translocation lines. We transferred Yr4EL into three wheat cultivars SM482, CM42, and SM51, and their progenies were all resistant to stripe rust, which can be used in future wheat resistance breeding programs.