C9. Genetic resources for food and agriculture

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.




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.


Figure C9bi. Cumulative Enrichment Index of plant genetic resource collections held in the UK and annual number of accessions, 1960 to 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 http://eurisco.ipk-gatersleben.de/apex/f?p=103:1; 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

indicator improving

indicator improving

No change (2018)


Genetic diversity is an important component of biological diversity.  The genetic diversity of UK plant resources includes domesticated plants and their wild relatives, as well as socio-economically and culturally valuable plant species.  These encompass plants grown in a farming or horticultural setting, or both, as well as commercial cultivars, landraces and traditional varieties and their wild relatives.  

Ex situ conservation of cultivated plants and their wild relatives is one method used to preserve genetic diversity.  In the context of this indicator, the term ex situ means off-site conservation of genetic material.

The Enrichment Index is a proxy measure of genetic diversity based upon the assumption that genetic diversity increases (to a greater or lesser extent) with originality of accessions, which is estimated based on: the number of species collected;  the number of accessions collected; the number of countries collected from; and the area from which collection took place.

As a result of discussions in the UK Plant Genetic Resources Group, a revised indicator is being considered; this was not available for 2018, but it is hoped that a new indicator will be available for the 2019 publication. 


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Last updated: July 2018

Latest data available:

Enrichment Index – June 2018;

Millennium Seed Bank – December 2017