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C9b. Plant genetic resources – Enrichment Index

Type: State / Benefits Indicator

Indicator Description

Seed banks provide an insurance policy against the extinction of plants in the wild. They complement in situ conservation methods, which conserve plants and animals directly in the wild. The indicator is based on an enrichment Index developed by the United Nations Food and Agriculture Organisation (FAO 2010) to assess the genetic diversity held in gene banks. The method factors in duplication and similarity to existing accessions. An upward trending line indicates diversity is being added to collections – the steeper the line, the greater the diversity being incorporated. An accession is a collection of plant material from a particular location at a point in time.


  1. Summary


No update since previous publication.

There is considerable annual variability in the number of new accessions into UK germplasm collections. The total number of accessions has risen since 1960, totalling 93,786 accessions by June 2018. 

There was a 15% increase in the Enrichment Index between 2013 and 2018. A rapid rise in the Enrichment Index since 2000 can be attributed to a concerted collection effort by the Millennium Seed Bank.

Figure C9bi.  Cumulative Enrichment Index of plant genetic resource collections held in the UK and annual number of accessions, 1960 to 2018

A combined bar and line chart showing the cumulative enrichment index of plant genetic resource collections held in the UK between 1960 and 2018. There is considerable variability in the number of new accessions into UK germplasm collections between 1960 and 2018.


  1. Data was obtained from EURISCO, which collates information across Europe from national germplasm collections, including the UK National Inventory of Plant Genetic Resources. The UK National Inventory includes food crop genetic resources such as crops, forages, wild and weedy species (including crop wild relatives), medicinal and ornamental plants, but does not include forest genetic resources.
  2. The UK 2018 update of EURISCO includes information which had previously not been submitted as a result of improvements within the holding institutes to catalogue their holdings. The indicator is therefore not directly comparable with the versions previously published.

Source: EURISCO Catalogue; date of data download 7 June 2018; based on UK contributions from: Genetic Resources Unit, Aberystwyth; Heritage Seed Library, Garden Organic; Commonwealth Potato Collection, The James Hutton Institute; Germplasm Resources Unit, John Innes Centre; Nottingham Arabidopsis Stock Centre; Millennium Seed Bank Partnership; Science and Advice for Scottish Agriculture, Scottish Government; Warwick Crop Centre, Genetic Resources Unit.

Assessment of change in status of ex situ conservation of cultivated plants and their wild relatives


Long term

Short term

Latest year

Cumulative Enrichment Index



No change (2018)



Download the Fiche, Datasheet and Technical background document from the JNCC Resource Hub

Last updated: July 2018

Latest data available:          

Enrichment Index – June 2018;

Millennium Seed Bank – December 2018.




UK Biodiversity Indicators 2019

Published: .

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