Healthy Agriculture Starts with Healthy Seeds
11 May 2022
Genebanks and germplasm health units play a key role in ensuring plant health by protecting their seed collections from pests and diseases and by sharing seeds that are free of pests and pathogens with breeders and farmers around the world so they can develop and grow new, resilient crop varieties.
Healthy plants are the foundation for all life on Earth, ecosystem functions, food security and nutrition, recognizes a United Nations resolution that designated May 12 as the International Day of Plant Health.
It’s an important recognition, especially given that each year, 20 to 40 percent of agricultural production is lost to pests and disease attacks, with an estimated economic value of USD 220 billion.
Without healthy plants, we cannot grow enough nutritious food to feed the growing global population and prevent malnutrition.
And plant health begins in genebanks. More specifically, in germplasm health units (GHUs), which make sure the seeds and other plant materials genebanks share with farmers, scientists and plant breeders are free of pests and diseases.
The contributions of these labs and the people who work in them are often overlooked. Pests and diseases contribute to the severe destruction of biodiversity. Human activities transport plants and plant products across borders and regions, of course, but natural causes like winds and insects can also cause diseases to spread globally.
Transboundary – or foreign – pests are responsible for destructive epidemics that aggravate the loss of native biodiversity. Invasive pests like fall armyworm and banana bunchy top virus in Africa have been estimated to cause an annual loss of USD 6.9 to 9.4 and USD 0.2 to 0.6 billion, respectively.
The good news is there is a range of efforts to protect plants from pests and diseases and minimize production losses. Genebanks protect plant health and biodiversity from pests and diseases by conserving the diversity of crops and making it available for use.
For instance, cassava landraces in East Africa under threat from the emerging cassava brown streak virus have been collected for safe conservation in genebanks. Similarly, global efforts to conserve taro in genebanks were made to protect it from leaf blight disease, which almost wiped the crop out in the South Pacific islands in the 1990s.
The diversity in genebanks can also be mined for useful traits that can then be used in breeding programs to develop high-yielding varieties that are resistant to pests and diseases. Assessing potato landraces for late blight resistance and banana collections for resistance to the bunchy top virus are a couple of examples of genebanks conserving plants that are less susceptible to diseases, and using these plants to develop new, more resilient varieties.
Genebanks acquire this incredible diversity by collecting plants in centers of crop diversity. The 11 CGIAR genebanks are at the forefront of this task, collectively conserving more than 760,467 samples of cereals, grain legumes, forages, tree species, root and tuber crops and bananas, representing 174 genera and more than 1,000 species.
These represent the largest international genebank network conserving important crops species feeding the world. The CGIAR genebanks distribute over 100,000 plant samples per year, and more than 80 percent of the recipients are in developing countries.
But plants and seeds can harbor pathogens and pests. Their shipment across borders has been recognized as an important pathway for the spread of pests and pathogens. Though countries can quarantine plants upon arrival, sometimes that’s not enough to prevent and manage invasive pests.
National quarantine capacities to prevent and manage invasive pests are not sufficient in much of Africa, and in parts of Latin America, the Middle East, and Central Asia, exposing global biodiversity hotspots in these regions to invasive pest risks. The bulk of CGIAR activities is concentrated in these regions.
That’s why GHUs, established by the CGIAR in each of their research centers, are so important. They help avoid the threat of pest and disease spread, especially viruses, with the transfer of plants from one country to another.
The GHUs, which work in close collaboration with host country quarantine authorities, facilitate the safe import and export of germplasm from CGIAR genebanks and breeding programs.
GHUs employ robust and sophisticated phytosanitary and seed health testing procedures to generate clean germplasm for conservation and international distribution. These units have been in operation for about 50 years and employ more than a million diagnostics assays per year to ascertain health status before plant materials are shared with users.
Through this process, GHUs can identify and intercept the average of eight percent of samples that are contaminated, which are then eliminated and replaced with clean stocks for distribution.
GHUs have been a vital conduit for international crop improvement programs, which test thousands of seed samples and new breeding lines annually in multiple environments to develop pest and disease resilient varieties. For instance, the International Wheat Improvement Network organizes several field trials every year to develop resistance to the wheat stem rust known as UG99.
The GHUs, through their expertise and network, also contribute to the first detection of pest and pathogens and provide information to national and regional surveillance programs, develop procedures for seed health testing, and contribute to the development of national phytosanitary capacity.
For example, genebanks and GHUs are partnering with the Crop Trust’s Seeds for Resilience project to enhance the capacity of five national genebanks in Africa for the safe conservation and sharing of seed samples.
GHUs enable national program partners and international breeding programs to have safe and efficient access to genetic resources and breeding materials and thus contribute to food production and livelihoods. The GHU’s contribution in the case of the development of rice blast resistance varieties in Bangladesh has been estimated at to have been 112 times what it cost.
Collectively, CGIAR Genebanks and GHUs make an invaluable contribution to plant health, biodiversity protection, and sustainable agricultural development. On May 12, let’s celebrate them too.
The opinions expressed here are those of the author(s) and do not necessarily reflect the opinions or views of the Crop Trust. The Crop Trust is committed to publishing a diversity of opinions on crop diversity conservation and use.
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