Cytogenetic and Genomic Characterization of a Novel Wheat-Tetraploid Thinopyrum elongatum 1BS⋅1EL Translocation Line with Stripe Rust Resistance

Dandan Wu,Xin Zhao,Yangqiu Xie,Lingyu Li,Yinghui Li,Wei Zhu,Lili Xu,Yi Wang,Jian Zeng,Yiran Cheng,Lina Sha,Xing Fan,Haigin Zhang,Yonghong Zhou, andHuoyang Kang

Abstract

Stripe rust, caused byPuccinia striiformisf. sp.tritici, is a destructive wheat disease pathogen.Thinopyrum elongatumis a valuable germplasm including diploid, tetraploid, and decaploid with plenty of biotic and abiotic resistance. In a previous study, we generated a stripe rust-resistant wheat-tetraploidTh. elongatum1E/1D substitution line, K17-841-1. To further apply the wild germplasm for wheat breeding, we selected and obtained a new homozygous wheat-tetraploidTh. elongatumtranslocation line, T1BS⋅1EL, using genomic in situ hybridization, fluorescence in situ hybridization (FISH), oligo-FISH painting, and the wheat 55K single nucleotide polymorphism genotyping array. The T1BS⋅1EL is highly resistant to stripe rust at the seedling and adult stages. Pedigree and molecular marker analyses revealed that the resistance gene was located on the chromosome arm 1EL of tetraploidTh.elongatum,tentatively namedYr1EL. In addition, we developed and validated 32 simple sequence repeat markers and two kompetitive allele-specific PCR assays that were specific to the tetraploidTh. elongatumchromosome arm 1EL to facilitate marker-assisted selection for alien 1EL stripe rust resistance breeding. This will help us explore and locate the stripe rust resistance gene mapping on the 1E chromosome and deploy it in the wheat breeding program.