Genomic selection in a kiwiberry breeding programme: integrating intra- and inter-specific crossing

Area of Science:

• Plant breeding
• Genomics
• Quantitative genetics

Background:

• Inter-specific hybridization in the genus Actinidia is common and utilized in breeding programs.
• Hybridization increases genetic diversity, incorporating desirable traits into new cultivars.

Purpose of the Study:

• To explore genomic prediction in Actinidia breeding, specifically comparing intra-specific and inter-specific crosses.
• To analyze the impact of sample size and population structure on predictive ability in genomic selection.

Main Methods:

• Utilized a linear mixed model with a marker-based relationship matrix.
• Analyzed four quantitative traits across intra-specific (A. arguta) and inter-specific (A. arguta x A. melanandra) crosses.
• Assessed variance components, heritability, and predictive ability, considering sample size and population structure.

Main Results:

• Continuous trait distributions indicated a polygenic background in both cross types.
• Reduced sample size correlated with decreased predictive ability.
• Population structure significantly impacted predictive ability, especially in inter-specific crosses.
• Inter-species effects influenced the prediction confidence of genomic estimated breeding values.

Conclusions:

• Genomic prediction in hybrid Actinidia populations presents challenges due to population structure and sample size imbalances.
• Understanding prediction accuracy in inter-species crosses is crucial for optimizing genomic selection strategies.
• Findings provide valuable insights for future breeding programs utilizing inter-specific hybridization.