Find in Library

Heading date (HD) is an important trait for wide adaptability and yield stability in wheat. The Vernalization 1 (<i>VRN1</i>) gene is a key regulatory factor controlling HD in wheat. The identification of allelic variations in <i>VRN1</i> is crucial for wheat improvement as climate change becomes more of a threat to agriculture. In this study, we identified an EMS-induced late-heading wheat mutant <i>je0155</i> and crossed it with wide-type (WT) Jing411 to construct an F₂ population of 344 individuals. Through Bulk Segregant Analysis (BSA) of early and late-heading plants, we identified a Quantitative Trait Locus (QTL) for HD on chromosome 5A. Further genetic linkage analysis limited the QTL to a physical region of 0.8 Mb. Cloning and sequencing revealed three copies of <i>VRN-A1</i> in the WT and mutant lines; one copy contained a missense mutation of C changed to T in exon 4 and another copy contained a mutation in intron 5. Genotype and phenotype analysis of the segregation population validated that the mutations in <i>VRN-A1</i> contributed to the late HD phenotype in the mutant. Expression analysis of C- or T-type alleles in exon 4 of the WT and mutant lines indicated that this mutation led to lower expression of <i>VRN-A1</i>, which resulted in the late-heading of <i>je0155</i>. This study provides valuable information for the genetic regulation of HD and many important resources for HD refinement in wheat breeding programs.