Genome-wide association study of seven agronomy traits under drought-stressed and well-watered in maize

Drought is one of the main factors restricting the increase of maize yield. Many genes respond to drought at seedlings have been cloned but less were effective in field. So, more work of understanding the genetic basis of drought response in field experiment need to be done due to its complexity. Herein, we constructed an association panel to carry on genomic wide association mapping for seven important traits under well-watered at whole period and drought at flowering stage. Then, 117 SNPs were identified, 50 SNPs of which were co-located among these traits or treatments or environments, including 50 SNPs identified under drought and 67 SNPs under well-watered. After merging the co-located SNPs, 90 SNPs were obtained. Combining the RNA-seq data of maize inbred line B73 under drought stressed from the public database, 31 differential expressed genes around the associated SNP were considered as drought responsive genes. Through protein interaction analysis and Gene Ontology enrichment analysis, it was shown that these genes are involved in regulating biological processes such as the tricarboxylic acid cycle, glycolysis, cell mitosis, and flowering signaling. And as the aggregation of related favorable allele genes improves the drought tolerance of materials. These results provide some candidate genes for in-depth analyzing the drought resistance mechanism when the drought happened at flowering stage during field experiment.

The online version contains supplementary material available at 10.1007/s11032-025-01599-5.