High-Resolution Mapping of the Novel Early Leaf Senescence Gene in Common Wheat.

Early leaf senescence negatively impacts the grain yield in wheat ( L.). Induced mutants provide an important resource for mapping and cloning of genes for early leaf senescence In our previous study, , a single incomplete dominance gene, that caused early leaf senescence phenotype in the wheat mutant LF2099, had been mapped on the long arm of chromosome 2B. The objective of this study was to develop molecular markers tightly linked to the gene and construct a high-resolution map surrounding the gene. Three tightly linked single-nucleotide polymorphism (SNP) markers were obtained from the Illumina Wheat 90K iSelect SNP genotyping array and converted to Kompetitive allele-specific polymerase chain reaction (KASP) markers. To saturate the region, the Axiom® Wheat 660K SNP array was used to screen bulked extreme phenotype DNA pools, and 9 KASP markers were developed. For fine mapping of the gene, these KASP markers and previously identified polymorphic markers were analyzed in a large F population of the LF2099 × Chinese Spring cross. The gene was located in a 0.24-cM genetic region flanked by the KASP markers AX-111643885 and AX-111128667, which corresponded to a physical interval of 1.61 Mb in the Chinese Spring chromosome 2BL containing 27 predicted genes with high confidence. The study laid a foundation for a map-based clone of the gene controlling the mutation phenotype and revealing the molecular regulatory mechanism of wheat leaf senescence.