Quantitative genetic study uncovers 22 yield QTL and protective proxy traits in maize, indicating that selecting for delayed senescence improves yield under heat and drought stress.
Key Points
Dissect the genetic basis of grain yield and correlated physiological proxy traits in dent maize under suboptimal and abiotic stress environments.
Developed a Multi-parent Advanced Generation Inter-Cross (MAGIC) population of 388 doubled-haploid (DH) lines derived from eight dent maize founders selected from a European diversity panel.
Genotyped the lines via whole-genome sequencing at ~5× coverage and evaluated them across seven testcross and 14 line per se field trials for grain yield, leaf senescence, leaf rolling, anthesis-silking interval, and six other agronomic traits.
Identified 22 quantitative trait loci (QTL) for grain yield that accounted for 45% of the total genetic variance across trials.
Observed significant correlations under heat and drought stress between testcross grain yield and line per se leaf senescence and leaf rolling, with favorable alleles at shared QTL promoting both delayed senescence/reduced rolling and higher yield.
Incorporating leaf proxy traits into bivariate and multi-trait genomic prediction models improved yield prediction accuracy over single-trait models.