Deciphering the Genetic Architecture of Color Variation in Whole Grain Rice by Genome-Wide Association

Area of Science:

• Plant genetics
• Agricultural science
• Nutritional science

Background:

• Whole grain rice offers superior nutritional benefits over polished rice.
• The pericarp color of whole grain rice (brown, red, black) impacts taste and commercial appeal.
• Current color attributes in whole grain rice are often undesirable and require improvement.

Purpose of the Study:

• To understand the genetic underpinnings of color variation in whole grain rice.
• To identify specific genetic loci and genes influencing rice pericarp color.
• To aid genomic breeding efforts for enhancing rice appearance and commercial value.

Main Methods:

• Genome-wide association analysis (GWAS) was performed on 682 rice accessions.
• Analysis focused on three color parameters: brightness, redness, and yellowness.
• Near-isogenic lines were used to validate significant single nucleotide polymorphism (SNP) regions.

Main Results:

• Twenty-six loci associated with grain color parameters were identified, indicating polygenic control.
• Eighteen loci/SNPs were detected in a subset excluding pigmented rice, with many being novel findings.
• Three candidate genes within significant SNP regions were identified as potentially involved in the flavonoid metabolic pathway.

Conclusions:

• Genetic variation significantly influences whole grain rice pericarp color.
• Novel genetic loci and candidate genes provide targets for improving rice grain appearance.
• Findings support the use of genomic breeding to enhance the commercial quality of whole grain rice.