Genetic diversity in European Pisum germplasm collections

Area of Science:

• * Agricultural Science
• * Genetics
• * Plant Breeding

Background:

• * Understanding the genetic diversity within *Pisum* germplasm collections is crucial for crop improvement.
• * Previous studies have offered insights into the genetic structure of *Pisum*, but comprehensive characterization across multiple collections is needed.
• * Identifying novel genetic variation is essential for developing resilient and high-yielding pea varieties.

Purpose of the Study:

• * To determine the relatedness and genetic diversity among *Pisum* genotypes across seven European genebanks.
• * To test and refine existing hypotheses regarding the structure of genetic diversity in *Pisum*.
• * To identify sources of novel genetic variation and propose reference sets for future research.

Main Methods:

• * Molecular marker analysis using retrotransposon insertions.
• * High-throughput microarray and Simple Sequence Repeat Amplification Polymorphism (SSAP) techniques were employed.
• * Analysis of 4,538 *Pisum* accessions from seven European genebanks.

Main Results:

• * Characterization of genetic diversity among 4,538 *Pisum* accessions revealed a broad continuum with graded sub-populations.
• * Distinct genetic groups were identified, corresponding to named taxa, and *Pisum sativum* cultivars/landraces were divided into two types.
• * Modest additions to overall diversity were observed with new germplasm, suggesting most *Pisum* genetic diversity is now described.

Conclusions:

• * The genetic diversity of *Pisum* forms a continuum with distinct sub-populations, refining previous interpretations of its structure.
• * Novel genetic variations were identified, offering valuable resources for breeders.
• * Reference sets of core *Pisum* accessions are proposed for future research and exploitation.