An enrichment index has been developed in order to measure the dynamics of the bio- and geographical diversity contained within ex-situ collections across time. The indicator is currently under development and has been tested against an ex situ collections dataset pooled from EURISCO (European National Inventories), USDA, ICRISAT, CIAT and SINGER (excluding ICRISAT and CIAT) data.

The enrichment index weights the pool of accessions entering the collection each year according to their originality when compared to the accessions already present in the collection. All accessions will increase the value of the index; the degree of increase however will depend on the originality of the accessions being added. The originality of each accession is based on two criteria: the taxon (genus + species fields) and the country of origin from which the accession was collected. The accessions weight for each year is estimated individually for each accession and summed for all accessions entering the collection.

Correlation analyses were conducted to test the index’s ability to reflect collection enrichment in terms of number of species/new species entering the collection, and of number of countries/new countries represented by the pool of accessions entering the collection. These showed that the index represents well the number of accessions, the number of species, the number of new species and the number of countries.

The index was calculated on a pooled global dataset representing 2.2 m accessions out of the 7.4 m reportedly stored ex situ world-wide (see the FAO’s Second Report on the State of the World’s PGRFA). It remains to be applied to individual national and international genebank collections as well as crop collections.

An increase in the index represents the addition of accessions to ex situ collections. The steepness of the line does not directly represent the number of accessions added and instead indicates the diversity being incorporated into collections. A steeper line indicates that greater novelty is being added to collections in regard to both taxonomy and source country. A horizontal line indicates that no accessions are being added to collections.

Any increase in the index will be beneficial in protecting genetic resources for food and agriculture. A steeper line however indicates a greater response from governments in terms of conserving the diversity of genetic resources and ensuring food security.

‘Ex situ conservation represents the most significant and widespread means of conserving PGRFA. There are now more than 1, 750 individual genebanks worldwide. These genebanks maintain about 7.4 million accessions, a 1.4 million increase since 1996. However, it is estimated that less than 30 percent of the total number of accessions conserved in ex situ collections are distinct, with the majority being duplicates held either in the same or, more frequently, a different collection. While the number of accessions of minor crops and crop wild relatives (CWR) has increased in the past 14 years, these categories are still generally underrepresented in ex situ collections.’

The developed indicator will incorporate data at a variety of levels, including the crop collection and gene bank levels and as a result national and regional versions of the indicator can be produced. For more information about producing regional and national ex situ crop collection indicators contact Stefano Diulgheroff at FAO (stefano.diulgheroff@fao.org).