QTL mapping and GWAS for field kernel water content and kernel dehydration rate before physiological maturity in...

Area of Science:

• Plant Genetics
• Agricultural Science
• Maize Breeding

Background:

• Kernel water content (KWC) and kernel dehydration rate (KDR) are critical for maize seed quality and mechanical harvesting efficiency.
• Identifying genes controlling these traits before physiological maturity is essential for breeding improved maize varieties.

Purpose of the Study:

• To map quantitative trait loci (QTLs) and identify candidate genes associated with KWC and KDR in maize.
• To provide a foundation for marker-assisted breeding of maize varieties suitable for mechanical harvesting.

Main Methods:

• Utilized 120 double-haploid (DH) lines derived from low-KWC and high-KWC parents.
• Constructed a linkage map using 1702 SNP markers and employed genome-wide composite interval mapping (GCIM) and multi-locus random-SNP-effect mixed linear model (mrMLM).
• Performed Gene Ontology (GO) analysis to identify candidate genes.

Main Results:

• Detected 10 QTLs and 27 quantitative trait nucleotides (QTNs) for KWC and KDR.
• Identified QTL hotspot regions on Chromosomes 3 and 7.
• Enriched 2 GO terms for biological processes and pinpointed 6 candidate genes.

Conclusions:

• The study successfully mapped genetic loci influencing maize kernel dehydration traits.
• Identified candidate genes provide valuable targets for marker-assisted selection in breeding programs.
• Findings offer theoretical support for developing maize varieties optimized for mechanical harvesting.