Flowchart

Care must be taken when interpreting information on current germplasm conserved ex situ. In many cases the coordinates are wholly or partly missing, imprecise or wrong. Moreover, the material held might be incorrectly identified, it might not be representative of the genetic diversity of the sampled population, it might be duplicated in several institutions giving a false idea of the actual genetic diversity being conserved, it may, for various reasons, be unavailable to potential users, some collections might not be efficiently managed and therefore records may contain errors, and the germplasm might not be managed to international genebank standards. The requirement for germplasm users to routinely sign Material Transfer Agreements as part of ITPGRFA obligations may for certain uses (e.g. commercial breeding companies) limit access to material as the user may not wish to draw attention to the material they are accessing from genebanks.

Source: Maxted et al. (1995), Hijmans et al. (1999)

Information on CWR occurrence is available from a wide range of sources, from herbarium and germplasm collections of the target taxon from the target area to relevant literature (monographs, revisions, field guides, floras, articles, papers). However, retrieving it presents a number of challenges:

• Herbarium and germplasm CWR occurrence data often involves visiting the herbarium or genebank to collect the data, which might not always be possible due to financial resources or time constraints.

• In recent years there has been an exponential growth of web-enabled ecogeographic datasets, helping researchers to survey herbaria and genebanks more easily. Most notably the Global Biodiversity Information Facility (GBIF), established in 2001, provides extensive access to global taxon nomenclature, taxon and accession distribution and conservation and environmental data. However, CWR themselves are not tagged in this resource and so searching for CWR occurrence data must be done through querying by country of origin and/or by CWR taxon name.

• In other existing databases, such as those managed by plant genebanks, the problem presented above also applies: CWR accessions are not identified as CWR. This issue is not helped by the fact that in the current FAO/IPGRI Multi-crop Passport Descriptors V. 2 used by many genebanks, the SAMPSTAT descriptor allows for designation of wild species samples but does not make a distinction between CWR and other wild species.

• The Crop Wild Relative Global Occurrence Dataset has been developed under the project Adapting Agriculture to Climate Change: Collecting, Protecting, and Preparing Crop Wild Relatives and includes a total of 5,647,442 georeferenced occurrence records from 80 crops gene pools (both crops and their wild relatives) (Castañeda-Álvarez et al. 2014). The data included in this database was gathered from more than 100 data providers (including GBIF). Although a great source of CWR occurrence data, care should be taken if using this database alongside further surveying of individual herbaria and genebanks, as it is likely that duplicate records (as well as duplicate accessions/herbarium vouchers) will be gathered. It is important that these are identified during the data verification stage of the ecogeographic study.

• While information on CWR per se is very specific to the PGR conservation and use community, because they are wild species they are also collected, conserved and studied by a broad community of taxonomists, ecologists, geneticists and physiologists etc. Therefore, these communities should be consulted when collating CWR occurrence data as they often have significantly larger datasets than the PGR community itself.

These challenges are not insurmountable but they do demand a carefully considered approach (particularly with regard to obtaining information from non-PGR communities) and a considerable amount of time. Nonetheless, it should be emphasized that the more occurrence data that is available, the more reliable and relevant the results of the analysis in formulating effective conservation plans.

Occurrence data should be collated using standard descriptors. A descriptor may be defined as “any attribute referring to a population, accession or taxon which the conservationist uses for the purpose of describing, conserving and using this material”. Descriptors are abstract in a general sense, and it is the descriptor states that conservationists actually record and utilize. Standard descriptors for occurrence data have been compiled and reviewed in the Occurrence Data Collation Template, while formal characterization and evaluation descriptors are associated with various standardized ‘Crop descriptor lists’ published by FAO, Bioversity, UPOV – however, these may or may not be suitable for describing the crop’s associated CWR. The use of well-defined, tested and rigorously implemented descriptor lists for scoring descriptors considerably simplifies all operations concerned with data recording, such as updating and modifying data, information retrieval, exchange, data analysis and transformation. This ensures uniformity, while reducing errors and problems associated with text synonyms and saves a considerable amount of time and effort associated with data entry.