CWR In Situ Strategy Helpdesk

National CWR flora methodology

Step 1: Creating the national CWR inventory

The starting point for preparing a national CWR conservation strategy is the national CWR inventory, which is likely to be derived from a national botanical checklist. Most countries have some form of floristic checklist, even if it is relatively old and not digitized. Useful information for a floristic checklist for any target area can be identified using two country-based lists of the world’s Floras; namely, Davis et al. (1986) and Frodin (2001), while Prendergast (1995) also lists other published sources of information on wild species. For areas where there is no adequate Flora or the Flora is written in an unfamiliar language, it may be possible to make use of the Flora of a neighbouring region. Thus, for example, the Flora of Turkey lists many of the species found in Syria. However, this approach must be taken with caution as there will be taxa present in neighbouring countries that are absent in the target country, and vice versa.

For the UK national CWR strategy (Maxted et al., 2007), the inventory was derived from the Crop Wild Relative Catalogue for Europe and the Mediterranean (Kell et al., 2005), which in turn was derived from Euro+Med PlantBase (Euro+Med PlantBase, 2005)—a digitized database of the European and Mediterranean flora. The basic UK CWR inventory was extracted from this Catalogue using a country filter. However, some editing of the inventory was necessary in order to standardize the nomenclature used by Euro+Med PlantBase to that applied within the UK using the standard national Flora (Stace, 1997). In the case of the UK and other European countries, access to a digitized regional flora is obviously a great aid to the creation of a national CWR inventory. However, for other regions of the world, the availability of such data is less likely. Nonetheless, many countries are now in the process of digitizing their Floras (if they have not done so already) and, given access to these data, national PGR programmes can fairly easily create their CWR inventories, as described below.

Having identified the national botanical checklist, the CWR can be extracted by applying a definition of a CWR to the taxa in the list. Maxted et al. (2006) have proposed a precise definition of what constitutes a CWR, but to apply this definition requires detailed knowledge of the taxonomy and/or genetic diversity of each CWR taxon. It would therefore be difficult to apply this precise definition to an entire country’s flora, so pragmatically, it may be necessary to apply the general definition of a CWR, as discussed by Maxted et al. (2006) and as applied in the creation of the CWR Catalogue for Europe and the Mediterranean (Kell et al., 2005, 2008). Broadly speaking, because the taxa found in the same genus as a crop are by definition in close taxonomic proximity to the crop, they may be regarded as CWR taxa. Using this broad definition, the process of producing a national CWR inventory is one of identifying which genera contain crop taxa and extracting the taxa within those genera from the national botanical checklist.

For countries included in the Euro-Mediterranean region, the national CWR inventory can be extracted from the CWR Catalogue for Europe and the Mediterranean (see PGR Forum, 2005). For countries in other regions, a global list of agricultural and horticultural crop genera can be extracted from Mansfeld’s World Database of Agricultural and Horticultural Crops (; Hanelt & IPK 2001), these genera can then be matched against the national botanical checklist, and all taxa within the matching genera extracted to produce the national CWR inventory (as described by Kell et al., 2008). Genus lists for forestry and ornamental taxa can also be added to create a more complete inventory. This approach is simplest if a digitized flora exists because the national flora can be more easily matched with the list of crop genera. However, for countries where no adequate flora or checklist exists, this approach cannot be applied so easily. Where this is the case, an alternative manual approach is to: a) agree a priority list of crops for a country, b) match these crops with known taxonomic treatments for the crop genera, and c) extract the wild species within the priority genera present in the country to generate the national CWR inventory. The digitized approach is comprehensive because all possible CWR taxa are encompassed, and the advantage of this approach is that it can be semi-automated. The manual approach is more ‘hands-on’ and is ideally facilitated by organizing a national workshop, including both taxonomists and crop experts. The crop experts define a list of important national crops (the definition of crops here can be broadened to include all socio-economically important species, if appropriate). Once the list of crop genera has been generated, the taxon experts produce a list of taxa present in the same genus as the priority crops to generate the national CWR inventory. This approach could be limited to include only native CWR taxa; however, as any CWR taxon present in the country may be of potential use in breeding, it is beneficial to include introduced taxa as well. This approach was recently successfully implemented for Bhutan (Tamang, 2004) and the Seychelles (Antoine, 2004). The digitized and manual approaches are summarized in Figure 2.


Figure 2. Two approaches to creating a national CWR inventory (Maxted et al., in prep.)

Having established the national CWR inventory, there are two routes for potential interactions with individual conservationists:

  • Sites or taxa of national importance can be identified and appropriate conservation action taken;
  • Individual conservationists, whether managing protected areas or collecting accessions for ex situ conservation, may consult the national CWR inventory to enact appropriate CWR conservation policies.

For example, as already noted, most protected areas are likely to have been established to conserve specific habitats or individual rare or threatened species; not explicitly to conserve CWR taxa. However, the manager can consult the national CWR inventory and match this against the species list for the protected area to generate a list CWR species present. If necessary, the manager can then adapt the management of the site to facilitate CWR conservation, where such changes do not conflict with the established management goals for the site. The manager may also wish to publicize the presence of CWR species in the protected area to the general public as a means of emphasizing its role; for instance, in helping to ensure national and global food security, as well as economic and environmental stability, through conservation of essential genetic resources.

As well as the need to raise the conservation priority of CWR within existing protected areas and to showcase the CWR species included, there is also a need as part of the national CWR conservation strategy to identify a number of key protected areas where CWR conservation is the predominant aim and to focus ex situ collection activities on the highest priority CWR taxa. The next steps are a recommended approach to determining how specific CWR protected areas might be identified and CWR taxa targeted for ex situ collection.

Step 2: Prioritizing CWR taxa/diversity

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