QTL Mapping for Heading Date and Yield-Related Traits in a Doubled Haploid Population Derived from Two Korean Wheat Cultivars

Understanding the genetics underlying heading date and yield-related traits is essential in wheat breeding for maximizing productivity under different environments. Using doubled haploid lines derived from two Korean wheat cultivars, we identified seven stable quantitative trait loci (QTLs) for yield-related traits, i.e., days to heading date (QDhd.jbnu-3B, QDhd.jbnu-6B, and QDhd.jbnu-7D), culm length (QCl.jbnu-6A), thousand kernel weight (QTkw.jbnu-6A), kernels per spike (QKps.jbnu-3B) and test weight (QTw.jbnu-1A). Compared to the lines carrying the allele for late heading, those carrying the allele for early heading at QDhd.jbnu-3B, QDhd.jbnu-6B, and QDhd.jbnu-7D headed 3.1, 2.0, and 1.7 days earlier, respectively. Interestingly, when the alleles for early heading at the three QTLs were accumulated, heading date was accelerated by approximately one week, indicating that these QTLs provide useful genetic resources to fine-tune heading date. However, as the alleles for early heading at all three QTLs were associated with decreased kernels per spike, caution is required when deploying them to minimize the negative impacts on yield. Our study provides useful information for developing wheat cultivars with optimal heading date and enhanced productivity.