Twenty-five years of international exchanges of plant genetic resources facilitated by the CGIAR genebanks: a case study on global interdependence

Between 1985 and 2009, germplasm conserved in the selected CGIAR genebanks was distributed to a broad range of users. According to the available data, 999,250 samples of 262,872 accessions belonging to 1470 different plant species were distributed during that period. The average number of samples distributed per year (39,970) is below that of the U.S. National Plant Germplasm System (NPGS), where total annual distributions have increased from around 120,000 (Bretting 2007) to more than 200,000 (Heisey and Day Rubenstein 2015) over the past few years. About 30 % of NPGS yearly distributions are typically to requestors from outside the U.S. However, in making this comparison, our lack of data from three important CGIAR genebanks should be kept in mind. Notwithstanding the missing data, the yearly volumes described are much higher than the average number of distributions of other important germplasm systems, such as the Russian Vavilov Institute (6400) (FAO 2009), the German Institute of Plant Genetics and Crop Plant Resources (4400 of barley only) (Ullrich 2011), the Centre for Genetic Resources in the Netherlands (2500) (Centre for Genetic Resources 2008), the Brazilian Empresa Brasileira de Pesquisa Agropecuária (1800) (Da Silva Mariante et al. 2009), the Institute of Crop Germpasm Resources in China (1550) (ICGR 2015), the Plant Genetic Resources Institute of Canada (1500) (Fowler and Hodgkin 2004). These numbers are useful for providing a general idea of the CGIAR’s relative contribution on the international scene, but they should be considered with caution because of the differences in the reporting periods and the limitations of our data.

Virtually all countries in the world have been involved in the exchange of germplasm. The materials listed in Table 1 were originally collected in, or provided by, at least 189 countries and distributed to at least 191 countries. In addition to distributions from the various genebanks, large amounts of germplasm in different stages of improvement have been sent out by the centres’ breeding programmes, although no system-wide mechanism has ever been set up to document these distributions over time. However, data provided by the centres³ for the fourth session of the ITPGRFA’s Governing Body indicate that from August 2008 to December 2009 these breeding programmes sent out over 500,000 samples (SGRP 2011). This amount points to the outstanding contribution that the CGIAR breeders make to international flows of germplasm, in addition to the centres’ genebanks.

According to data available through the GENESYS portal, which gathers information on numerous national and international genebanks, the international ex situ collections hosted by the CGIAR centres currently include 712,834 accessions of their mandate crops and related gene pools, originally collected from a vast number of countries (Appendix, Tables 6, 7, 8). The genebanks that were analysed in this study, currently host 445,785 accessions of 2848 species.⁴ Our data suggest that samples of roughly half the diversity held have been distributed at least once by these genebanks.

During the period analysed, there appears to be have been a slight downward trend in the overall number of samples distributed, as already highlighted elsewhere (Halewood et al. 2013). A similar decline was observed in the diversity of the materials distributed, which was measured according to the number of accessions distributed and the number of species represented (Table 3). This trend may be attributed to the fact that the requests became more targeted as more characterization and evaluation data became available, which led to breeders and researchers making requests for smaller sets of materials (Halewood et al. 2013; López Noriega et al. 2013a). For those CGIAR genebanks actively distributing sets of materials for international adaptation trials, the decline could also be due to decreases in the funding made available for these multi-location field operations. It could be that some of the requests that were traditionally made to the CGIAR are now being directed to other genebanks. In addition to institutions that have always been at the forefront of international distributions, alongside the CGIAR, such as the US Department of Agriculture (USDA), a number of national institutions in other countries have been increasing their collections and may be receiving more germplasm requests (FAO 2010). In addition, some private sector users—those most likely to apply some form of intellectual property rights to the final PGRFA products—may have refrained in recent years from requesting germplasm from the CGIAR because of their reluctance to accept the benefit-sharing clauses of the MLS (Halewood and Nnadozie 2008). It is important to note that traditionally these companies have been an extremely small portion of the users of CGIAR materials, as described later.

According to GENESYS, over 50 % of the total germplasm distributed by the CGIAR genebanks over the 25 years analysed are landraces or traditional cultivars, which are predominant within these collections (Fowler et al. 2001; Genesys 2014). Breeding and research lines constitute less than 20 % of the materials distributed, while advanced or improved cultivars comprise only 7 % of the distributions. Wild and weedy relatives amount to 12 % of the samples sent out by the analysed genebanks, not only suggesting their importance as sources of useful traits but also reflecting the greater difficulty of using them in breeding compared to other materials (Fig. 1). The decision about which materials to conserve in the long term is made by each centre independently, often following the outcomes of economic analyses on the costs and benefits of conserving materials in genebanks or breeding programmes (Koo et al. 2004). The data in this study reveal that most centres give priority for long-term storage in their genebanks to materials that belong to the primary genepools – that is, the landraces and wild relatives of their mandate crops. This strategy also reflects the fact that all centres with genebanks also have breeding programmes that actively exchange research, breeding and improved lines with partners worldwide, making the conservation of these sets by the genebank neither necessary nor efficient. However, research, breeding and advanced lines are sometimes included in long-term collections, when the properties, or the use of the material, justify it. For instance, this may be the case with materials that have accumulated unique genetic properties (for example, allele combinations), those that are laborious to reproduce (for example, inter-specific hybrids) or those that are commonly used as benchmark varieties in evaluation trials.

Based on the number of samples per accession sent to recipients, there appears to be enormous variation in the popularity of any single accession. Almost 60 % of the accessions in the dataset have been distributed between two and ten times, while only 5.7 % (150 accessions) have been distributed more than 100 times. Most of the latter come from ILRI, CIP and ICRISAT and have been distributed to an average of over 38 countries (SD 20.5) (see Appendix, Table 9 for details on the top 50 most ‘popular’ accessions of our dataset). More than half of these frequently distributed materials are improved lines, whereas landraces, wild relatives and, to a lesser extent, breeding materials constitute the bulk of the accessions transferred less frequently. Among the possible reasons for the ‘popular’ materials to be more frequently requested (that is, by many institutions worldwide) is the fact that the characterization and/or evaluation data already accumulated on them increases their value for breeding and research. This information, in turn, facilitates their use including in institutions and countries with limited capacity or infrastructure for conducting lengthy and costly pre-breeding research using non-adapted populations and wild relatives (FAO 2010).

Of the total 189 countries from which material distributed by the seven CGIAR genebanks was obtained, 112 are developing countries, 54 are developed countries and 23 have economies in transition. Of the total 191 recipients, 116 are developing countries, 19 are economies in transition and 56 are developed countries. Data for developing countries and countries with economies in transition has been combined in our analyses. Both developed and developing countries are net recipients—that is, they receive more diversity than they contribute to international gene banks. While this ‘sink’ behaviour is more evident for developed countries, which tend to harbour comparatively less indigenous genetic diversity in their territories, the majority of global exchanges of germplasm mediated by the CGIAR genebanks is distributed South to South—that is, between developing countries (Fig. 2).

In their analysis of the flows from six of the CGIAR genebanks and from the USDA’s National Plant Germplasm System (NPGS) between 1990 and 1999, Smale and Kelly Day Rubenstein (2002) also observed that a predominance of developing countries and transition economies were providers and recipients. So too did the CGIAR’s System-wide Genetic Resources Programme (2011) in its biannual reports to the Governing Body of the ITPGRFA. Tables 4a, b provide more detail on the amount, diversity and geographical coverage of the distributions facilitated by the international genebanks for the top 25 provider countries and the top 25 recipient countries.

Almost all of the top providers listed in Table 4 are developing countries. Many of them are important centres of origin, domestication or diversification of the crops curated by the genebanks considered in this study, including India (rice, millet), Peru (potatoes), Syria and Turkey (wheat and barley), China (rice) and a number of African countries (particularly for tropical forages). Many of the top recipients are also developing countries, and, again, many of them are centres of origin or diversity of crops or forages that they have requested, underscoring the fact that even diversity-rich countries are not self-sufficient in terms of their PGRFA needs. As an example, the difference in the amount of germplasm flowing in and out of India, compared to other countries, stands out as very significant. India has provided and received massive quantities of germplasm. Interestingly, a significant percentage of the materials originally collected in, or obtained from, India ends up going back to Indian recipients (59 % of the samples and over 70 % of the accessions), which makes it the largest recipient of CGIAR-hosted materials originally obtained from within its own borders. A high percentage of ‘reabsorption’ of their own materials through CGIAR-mediated flows are also recorded for Tunisia and Morocco (48 and 42 % respectively), the Philippines (37 %), Iran and Jordan (30 and 25 %) and others to lesser extents. These observations highlight the additional benefit of germplasm deposited in international collections since it provides long-term secure conservation and availability of quality material (and often value-added characterization and evaluation data) originating from one’s own territory, in addition to access to diversity from hundreds of other countries. The latter benefit is particularly relevant for those countries with limited capacity to establish and maintain national conservation programmes for their own local materials.

Differences exist not only in the amount, but also in the type of materials provided by developed and developing countries. While developed countries provide an overall lower quantity of materials compared to developing countries, they contribute a proportionally higher share of materials for which some formal research, pre-breeding or other form of improvement has been conducted. In total, 27 % of the samples ‘distributed’ by our seven CGIAR genebanks from developed countries were research materials and improved/elite lines (with the United States supplying as much as 80 % of this category); only 14 % of the samples distributed from developing and transition countries belonged to these categories. On the recipient side, the share of germplasm that carried some degree of research and improvement flowing into developing countries and transition economies is 30 % of the overall incoming samples, while it is 14 % for developed countries.

In both developed and developing nations, public institutions (including the National Agricultural Research System (NARS), universities and genebanks) are by far the predominant recipients of CGIAR materials (Table 5; Fig. 3). These public sector recipients are located in developing countries in over 75 % of the cases. The share of samples sent to commercial companies is only around 3 % of the total, and the recipients are primarily (77 %) in developing countries.

These findings are also consistent with those of Smale and Day Rubenstein (2002) who found that most recipients of germplasm from the US NPGS, another important worldwide facilitator of PGRFA for research and breeding, were in the public sector. The volume and diversity of the PGRFA flows described in this study, albeit only a small sample of worldwide exchanges, demonstrate the extent of countries’ interdependence on PGRFA for crop improvement and, ultimately, food security. While acknowledging the limits of our dataset, we believe that the conclusions regarding the extent of international interdependence would likely have been even stronger had the data from important genebanks such as those at CIMMYT, CIAT and IITA been included. The emerging picture confirms an established description of modern agriculture as an interdependent network of seed and germplasm sources, in which very few countries or farming systems in the world do not rely to some degree on the international system that moves crop germplasm, breeding lines and improved varieties across international borders (Duvick 1984).

Analyses by other authors confirm these patterns, describing how crop improvement has benefited from access to a wide range of materials with different origins. Fowler, Smale and Gaiji (2001) undertook an analysis of CGIAR data focusing on a different time frame and different measures than those presented here. Smale et al. (2002) used the case of spring bread wheat released by national programmes in developing countries. Warburton et al. (2006) and Dreisigacker et al. (2005) looked at synthetic hexaploids to illustrate the significance of access to wild relatives from centres of diversity in wheat improvement. Voysest et al. (2003) took the case of beans in Latin America (Fowler et al. 2001; Smale et al. 2002; Voysest et al. 2003; Dreisigacker et al. 2005; Warburton et al. 2006). Additional studies have focused on those countries that are the centres of crop diversity. Rejesus et al. (1996) reported that 45.6 % of the germplasm used by wheat breeders in Western Asia, the Vavilov centre for the species, comes from international sources. Evenson and Gollin (1997) documented the dependence of Asian countries, including the Vavilov-centre countries such as India, Burma, Bangladesh, Nepal and Vietnam, on IRRI for rice germplasm of different provenance (65.0 % in India and 98.1 % in Vietnam) (Rejesus et al. 1996; Evenson and Gollin 1997). All of this evidence points to the ‘international public good’ nature of the materials held and made available by the CGIAR as well as by other actors who make such materials available. It highlights the importance of supporting the continuation and enhancement of conservation as well as the internationally facilitated sharing of germplasm within the framework of the ITPGRFA.