Genome-Wide Association Analysis of Effective Tillers in Rice under Different Nitrogen Gradients

Area of Science:

• Agricultural Science
• Genetics
• Plant Breeding

Background:

• Nitrogen is vital for rice yield, with effective tillering being a key agronomic trait.
• The genetic control of effective tillering under nitrogen stress is complex and requires further investigation.

Purpose of the Study:

• To identify quantitative trait loci (QTL) associated with effective tillering in rice under low and high nitrogen conditions.
• To pinpoint candidate genes responsible for effective tillering using genome-wide association analysis.

Main Methods:

• Genome-wide association analysis (GWAS) was performed on 469 rice germplasm varieties.
• QTLs were analyzed across different years and nitrogen treatments (low: 60 kg/hm², high: 180 kg/hm²).
• Candidate genes were identified using haplotype analysis and spatio-temporal expression patterns.

Main Results:

• Seven candidate genes (NAL1, OsCKX9, Os01g0690800, Os02g0550300, Os02g0550700, Os04g0615700, and Os04g06163000) were identified within QTL regions.
• These genes are considered the most likely contributors to effective tillering under varied nitrogen availability.
• QTLs detected across multiple conditions were prioritized.

Conclusions:

• The identified genes provide valuable targets for marker-assisted selection.
• This research facilitates strategies to control effective tillering for enhanced rice productivity.
• Understanding the genetic basis of tillering under nitrogen stress is crucial for crop improvement.