A comprehensive SPET-based linkage mapping for berry texture and defective seed development in grapevine

Area of Science:

• Plant genetics
• Viticulture
• Fruit breeding

Background:

• Grape berry texture and seed development are complex traits influenced by multiple genes.
• Understanding the genetic basis of these traits is essential for improving grape cultivars.

Purpose of the Study:

• To dissect the genetic architecture of berry texture and defective seed development in grapes.
• To identify quantitative trait loci (QTLs) associated with these traits using a high-density genetic map.

Main Methods:

• Phenotyping of an F1 population for berry traits, seed parameters, and texture.
• Genotyping using Single Primer Enrichment Technology (SPET) and construction of high-density pseudo-testcross genetic maps.
• Quantitative trait locus (QTL) analysis using BLUPs of phenotypic data.

Main Results:

• Identified 12 major QTLs on Sultanina chromosome 18 associated with berry texture and seed traits, explaining up to 65.49% of phenotypic variation.
• Detected several minor-effect QTLs in both parental lines, supporting the polygenic nature of berry mechanical properties.
• In silico analysis suggested candidate genes within QTL regions involved in berry texture and seed development regulation.

Conclusions:

• The genetic architecture of grape berry texture and seed development is largely polygenic.
• A strong link exists between seed development status and berry softening during ripening.
• Identified QTLs provide a foundation for future functional studies and marker-assisted breeding in grapevines.