Genetic Characterization by SSR Markers of a Comprehensive Wine Grape Collection Conserved at Rancho de la Merced...

Area of Science:

• Plant genetics and breeding
• Agricultural science
• Bioinformatics

Background:

• The IFAPA "Rancho de la Merced" repository holds one of Europe's oldest and most diverse grapevine germplasm collections.
• Exploring genetic variability is crucial for addressing agronomic traits and improving grapevine cultivation.
• Understanding grapevine genetic diversity aids in conservation and breeding efforts.

Purpose of the Study:

• To genetically characterize a wine and dual-use grapevine subcollection of 930 accessions.
• To identify unique genotypes, compare them with existing databases, and detect synonymies or mislabeling.
• To analyze the genetic structure, diversity, and origin of Spanish grapevine varieties within the repository.

Main Methods:

• Genetic analysis (DNA profiling) of 930 grapevine accessions.
• Comparison of genetic profiles with international databases.
• Clustering and structure analyses to determine genetic relationships and population structure.
• Analysis of Molecular Variance (AMOVA) to partition genetic variability.
• Proposal of a core collection representing overall allele richness.

Main Results:

• Identified 521 unique genotypes from 930 accessions, with 45 previously undescribed.
• Confirmed a total pool of 481 Vitis vinifera accessions, including table cultivars, and detected synonymies/mislabeling.
• Structure analysis revealed six clusters based on eco-geographic areas and one non-vinifera group.
• Spanish Mediterranean varieties are genetically closer to oriental genotypes than to European ones.
• High heterozygosity within groups significantly contributes to overall genetic variability.

Conclusions:

• The grapevine germplasm is well-structured, with significant genetic diversity.
• Spanish grapevine origins are complex, with connections to both oriental and European genetic pools.
• A proposed core collection of 13% of accessions effectively captures the repository's genetic richness.