Integrated GWAS and Fst analysis identify flowering-time regulatory genes in maize

Flowering time in maize is a complex quantitative trait regulated by multiple genes, and its genetic variation mechanisms remain to be fully elucidated. In this study, we phenotypically evaluated flowering-related traits (days to tasseling, days to pollen shedding, days to silking) across six different environments using an association population comprising 368 maize varieties. Genome-wide association studies were employed to dissect the genetic basis of these traits. A total of 261 significant association single nucleotide polymorphisms (SNPs; logarithm of odds > 5.5) were detected, among which 23 SNPs were consistently identified across multiple environments or traits. By integrating population fixation index, we further screened 41 potential candidate genes, including Zm00001d006213, Zm00001d027394, and Zm00001d027395, which are likely key regulators of flowering time. These findings provide both theoretical insights into the genetic regulatory network of maize flowering time and valuable gene resources for molecular breeding.