Strawberry cultivar identification based on hypervariable SSR markers

Area of Science:

• * Agricultural Science
• * Genetics
• * Plant Breeding

Background:

• * Strawberry (Fragaria × ananassa) genetic resources require robust genotyping methods for effective management.
• * Existing SSR markers may not offer sufficient polymorphism for precise cultivar discrimination.
• * Accurate genetic fingerprinting is crucial for protecting breeders' rights and maintaining germplasm integrity.

Purpose of the Study:

• * To evaluate the efficacy of two newly developed and two previously reported SSR markers for strawberry genotyping.
• * To assess the polymorphic information content of these SSR markers across diverse strawberry accessions.
• * To determine the utility of SSR markers for distinguishing cultivars, managing genetic resources, and safeguarding intellectual property.

Main Methods:

• * Genotyping of 75 strawberry accessions (72 cultivars/lines and 3 octoploid Fragaria species) using four SSR markers.
• * Analysis of electropherograms to assess marker interpretability and polymorphism.
• * Combination of markers to evaluate discrimination power, including for full-sib individuals.
• * Reproducibility testing using various tissue types (leaves, sepals, fruit flesh).
• * Principal coordinate analysis (PCoA) to visualize genetic relationships among accessions.

Main Results:

• * All four SSR markers produced interpretable electropherograms for all 75 accessions.
• * The markers exhibited high polymorphism, with one new marker (FxaHGA02P13) distinguishing all but a single mutant strain.
• * Combining two markers successfully distinguished all 48 full-sib individuals.
• * Fingerprinting patterns were reproducible across different tissue types.
• * PCoA revealed distinct groupings reflecting strawberry taxon and breeding origin.

Conclusions:

• * The evaluated SSR markers, particularly the novel ones, are highly effective for strawberry genotyping and cultivar discrimination.
• * These markers provide reproducible and reliable fingerprinting patterns suitable for diverse applications.
• * The developed SSR markers will significantly enhance strawberry genetic resource management and aid in the protection of breeders' rights.