Breeding resistant wheat (Triticum aestivum) cultivars is the most efficient way to manage wheat stripe rust, a highly destructive disease caused by the fungal pathogen Puccinia striiformis f. sp. tritici (Pst). Therefore, the exploration of new resistance genes is ongoing. The resistance gene Yr85 confers protection against predominant Pst races in China at all stages of plant development. Here, we fine-mapped Yr85 to a 0.12 cM interval between allele-specific quantitative PCR markers XK1B-61 and XK1B-65, corresponding to a 1.76 Mb region on chromosome 1BS in the IWGSC RefSeq v2.1 reference genome (wheat cultivar Chinese Spring), using 5507 F₅ plants derived from heterozygous F₄ plants, themselves descendants of an AvS × AvSYr85NIL cross. Haplotype analysis and whole-genome resequencing suggested that Yr85 may be from a distant source. Moreover, agronomic trait evaluation indicated that Yr85 is located in a chromosomal region lacking linkage drag. Genotyping of 309 Chinese wheat cultivars and lines with a marker that cosegregated with Yr85 during fine mapping identified one cultivar possibly carrying the resistance gene. Our findings indicate that Yr85 has potential for use in wheat-breeding programs in China. This study lays the foundation for map-based cloning and marker-assisted selection of Yr85.

Stay-green (SG) in wheat is a beneficial trait that increases yield and stress tolerance. However, conventional phenotyping techniques limited the understanding of its genetic basis. Spectral indices (SIs) as non-destructive tools to evaluate crop temporal senescence provide an alternative strategy. Here, we applied SIs to monitor the senescence dynamics of 565 diverse wheat accessions from anthesis to maturation stages over 2 field seasons. Four SIs (normalized difference vegetation index, green normalized difference vegetation index, normalized difference red edge index, and optimized soil-adjusted vegetation index) were normalized to develop relative stay-green scores (RSGS) as the SG indicators. An RSGS-based genome-wide association study identified 47 high-confidence quantitative trait loci (QTL) harboring 3,079 single-nucleotide polymorphisms associated with SG and 1,085 corresponding candidate genes. Among them, 15 QTL overlapped or were adjacent to known SG-related QTL/genes, while the remaining QTL were novel. Notably, a set of favorable haplotypes of SG-related candidate genes such as TraesCS2A03G1081100, TracesCS6B03G0356400, and TracesCS2B03G1299500 are increasing following the Green Revolution, further validating the feasibility of the pipeline. This study provided a valuable reference for further quantitative SG and genetic research in diverse wheat panels.