A modern ampelography: a genetic basis for leaf shape and venation patterning in grape

Area of Science:

• Viticulture and Plant Genetics
• Morphometrics and Computational Biology

Background:

• Terroir in Vitis vinifera is shaped by genotype, environment, and culture.
• Traditional ampelography relied on leaf morphology for cultivar identification, lacking genetic insights.
• Grape leaves display significant variation in blade outgrowth, hirsuteness, and venation.

Purpose of the Study:

• To conduct a morphometric analysis of grape leaf diversity.
• To investigate the genetic underpinnings of grape leaf shape and hirsuteness.
• To explore the potential of leaf traits as breeding targets for preserving terroir amidst climate change.

Main Methods:

• Morphometric analysis of over 1,200 grape accessions using Elliptical Fourier descriptors and Procrustes analysis.
• Heritability estimation to quantify the genetic component of leaf traits.
• RNA-Seq of mutant varieties and genome-wide association study (GWAS) to identify genes controlling leaf shape.

Main Results:

• Quantitative descriptions of grape leaf outlines and venation patterns.
• Confirmation of a significant genetic basis for leaf morphology and hirsuteness.
• Identification of a relationship between leaf morphology, hirsuteness, and climate adaptation.

Conclusions:

• Grape leaf diversity is underpinned by a strong genetic component.
• Leaf traits like morphology and hirsuteness are heritable and linked to climate.
• Targeting grape leaf traits in breeding programs may help preserve unique terroirs under climate change.