Strawberry soluble solids QTL with inverse effects on yield

Area of Science:

• Genetics
• Plant Breeding
• Biochemistry

Background:

• Strawberry sweetness is primarily determined by sugars.
• Genetic control of sugar content is crucial for developing improved cultivars.
• Understanding the genetic basis of soluble solids content (SSC) is vital for breeding programs.

Purpose of the Study:

• To identify genetic loci controlling soluble solids content (SSC) in strawberries.
• To investigate the relationship between SSC, yield, and sugar metabolism.
• To pinpoint candidate genes associated with sugar accumulation and transport in strawberry fruit.

Main Methods:

• Genome-wide association studies (GWAS) were conducted on 3399 strawberry individuals.
• Quantitative trait loci (QTL) analysis was performed to identify genetic regions linked to SSC.
• Metabolite profiling and expression quantitative locus (eQTL) mapping were used to identify candidate genes.

Main Results:

• Two stable QTL for SSC were identified on chromosomes 3B and 6A.
• Favorable alleles for SSC negatively impacted yield, but optimal combinations with reduced yield penalties were found.
• Variations in sucrose concentration and transport were observed, indicating genetic control over sugar accumulation during ripening.
• Starch synthase 4 and a sugar transporter 2-like gene were identified as candidate genes within the SSC QTL intervals.

Conclusions:

• Genomic regions and candidate genes influencing strawberry sweetness and yield have been identified.
• These findings facilitate genomics-assisted breeding for enhanced strawberry flavor.
• Further research into the identified candidate genes will elucidate the genetic mechanisms of sugar accumulation in strawberries.