The first step in the process of conserving crop diversity in genebanks is to locate and collect this diversity, from farmers’ fields and from the wild. Starting with the global collecting work of Nikolai Ivanovich Vavilov in the 1920’s, the world’s genebanks have identified varieties of crops and related species that were threatened or thought to be useful, collected them and conserved them. Many of these have since been used to develop, diversify, refine, or otherwise improve agriculture.
In the past fifty years or so it has become clear that crop diversity is being eroded from farmers’ fields no less than the wild, due to the continuing transition around the world from traditional to modern agriculture, and forces such as habitat destruction, desertification, and urbanization. Collecting has therefore taken on an added urgency, as genebank collections have in many cases become the sole remaining source of many traditional landraces and of some populations of wild species.
Collecting continues today, to identify diversity useful for agriculture and to conserve it before it is lost. Although the greater part of the diversity of many crops has probably been collected, there is still some way to go for some important crops. For example, only perhaps 35% of the diversity of cassava has been collected, according to experts on the crop. In addition, the wild species related to crops are in general not well represented in collections, and new species related to our major crops are still being discovered and described.
Recently, a new threat has come to the forefront. Climate change has increased the need for diversity, the raw material for crop adaptation. Ironically, this diversity, and in particular the wild relatives of crops, are increasingly threatened by climate change, as well as the forces of land use chance and habitat destruction. The need has never been greater to collect and conserve crop diversity.
In partnership with scientists at the Centro Internacional de Agricultura Tropical (CIAT) and Bioversity International, the Trust has developed a methodology to identify collecting priorities, based on gaps in the collections of major crop genepools worldwide. Researchers from CIAT, together with Trust staff, have recently published in PLoS1 the basic methodology for identifying collecting priorities for crop wild relatives, using Phaseolus bean as a model. Preliminary maps of priority areas for collecting and other information are available for the wild relatives of 12 globally important crops. Similar analyses for cultivated varieties (landraces) are also under development by CIAT researchers and others.
From 2009-2011, the Trust supported a competitive grant scheme for collecting plant genetic resources, entitled "Towards a more complete coverage of crop diversity in ex situ collections". The application window is now closed, but you can download document below to review the results of the award scheme, or click on the link below to search the technical results and outputs of the projects. The Trust now has a major global initiative to collect the wild relatives of 26 major crops, which are missing from the world’s genebanks. Crop wild relatives are particularly rich sources of diversity and are expected to contribute to the development of new varieties better adapted to changing climates.