Detection of QTNs for kernel moisture concentration and kernel dehydration rate before physiological maturity in...

Area of Science:

• Agricultural Science
• Genetics
• Plant Breeding

Background:

• Maize is China's largest grain crop, with mechanical harvesting crucial for production.
• Kernel moisture concentration (KMC) is a primary factor influencing mechanical maize harvesting efficiency.
• Kernel dehydration rate (KDR) is closely linked to KMC, making it a key trait for study.

Purpose of the Study:

• To conduct genome-wide association studies (GWAS) for KMC and KDR in maize.
• To identify quantitative trait nucleotides (QTNs) associated with KMC and KDR.
• To mine candidate genes related to KMC and KDR for future breeding efforts.

Main Methods:

• 132 maize inbred lines were used to measure KMC from 10 to 40 days after pollination (DAP).
• KDR was calculated based on KMC measurements.
• Genotyping was performed using a maize 55K single-nucleotide polymorphism array.
• QTNs were detected using five statistical methods within the mrMLM package.

Main Results:

• A total of 334 significant QTNs were identified for KMC and KDR.
• 175 QTNs were unique to KMC, and 178 were unique to KDR.
• 116 QTNs were detected by at least two methods, with 58 detected by more than two methods.
• Gene Ontology enrichment analysis of candidate genes near 14 QTNs revealed significant enrichment in cellular components, including five genes.

Conclusions:

• The study identified numerous QTNs associated with KMC and KDR in maize.
• These findings provide valuable genetic information for understanding and improving maize kernel dehydration traits.
• The identified QTNs and candidate genes can facilitate marker-assisted selection for enhanced maize harvesting.