Exploring intra-varietal variation for complex traits in grapevine (Vitis vinifera L.).

Area of Science:

• Plant genetics and breeding
• Viticulture and enology
• Agricultural science

Background:

• Grapevine (Vitis vinifera L.) production faces climate change challenges, necessitating adaptive breeding.
• Clonal propagation, while preserving varietal identity, limits genetic gain due to long breeding cycles.
• Understanding intra-varietal genetic diversity is crucial for improving grapevine adaptation and breeding efficiency.

Purpose of the Study:

• To assess phenotypic and genetic variation within eight key grapevine clonal populations.
• To estimate heritability, genetic correlations, and variance components for multiple traits.
• To evaluate the potential for enhancing clonal selection using advanced breeding strategies.

Main Methods:

• Analysis of 14 years of data on six agronomic, quality, and disease traits from eight grapevine varieties.
• Application of linear mixed models to estimate variance components and heritability.
• Calculation of genetic correlations between traits.

Main Results:

• Significant intra-varietal phenotypic variation was observed across all assessed traits.
• Moderate to high heritability estimates indicate substantial genetic influence on phenotypic variation.
• Substantial genotype-by-environment interactions were detected, influencing trait expression.
• Genetic correlations revealed complex positive and negative trait relationships.

Conclusions:

• High intra-varietal genetic diversity in grapevine is a valuable resource for breeding and adaptation.
• Predictive breeding tools (genomic and phenomic selection) can enhance clonal selection.
• Optimization-based multi-trait selection is recommended, especially given negative trait correlations.
• Maintaining varietal integrity while improving adaptation is achievable through informed selection strategies.