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The line of defense against the transboundary spread of pests and diseases

Plant improvement has always been an important component of food production and security. However, the impacts of climate change—higher temperatures, extreme and erratic weather, drought, increasing levels of carbon dioxide, and rising sea levels—have created a new urgency for global crop improvement efforts.

One of the effective ways to keep crop production stable despite new and unpredictable climate patterns is improved varieties developed through plant breeding. This is where the genetic diversity of plants becomes crucial to the sustainable development of new varieties for present and future challenges, according to the United Nations Food and Agriculture Organization (FAO).

Heirloom crop varieties have intrinsic value that comes in specific genes, according to Ruaraidh Sackville Hamilton, the former head of the T.T. Chang Genetic Resources Center at the International Rice Research Institute (IRRI) in the Philippines. Dr. Sackville Hamilton said breeders can generate a value that’s good for farmers just by virtue of its genetic properties and by combining these genetic properties into other varieties it is possible to make better varieties. Wild relatives of food crops are also a treasure trove of genetic materials essential for building new varieties that are sturdier and more adaptable to current climate conditions. Thus, access to the wide variety of plant germplasm resources is not only critical to the success of breeding programs but in the fight against global hunger.

“Germplasm refers to source plants which will be further multiplied for cultivation or as sources of unique genes,” Jan Kreuze, the head of the Crop and System Sciences Division at the International Potato Center, said during the CGIAR Webinar on Germplasm Health in Preventing Transboundary Spread of Pests and Pathogens. “These source plants are often sent around in internationally in small quantities and are subsequently multiplied and used in important countries.”

For this reason, it is important to ensure the source plants are healthy because otherwise whatever these are used for will have health problems, according to Dr. Kreuze.

“Germplasm with unique traits often come from the region of the origin of the species which is also likely to be the region of origin of its pests and diseases,” he said. Like other plant products, germplasm materials may carry these organisms. “This provides an additional risk of introducing these into other countries.”

Transboundary pest or disease can often have significant negative impacts on food security and nutrition in developing countries, according to the FAO. Its economic impact (estimated at about USD 540 billion) comes from yield losses or reduced efficiency of agricultural production that could be particularly severe if the local economy is heavily dependent on one or a few vulnerable crop or livestock.

Given that the CGIAR genebanks are responsible for over 80% of recorded germplasm transfers globally, it is imperative for the organization’s seed health groups to ensure the complete health of these germplasm materials.  The CGIAR genebanks and germplasm health units (GHUs) employ more than 400 skilled staff to monitor, test, germinate, multiply, characterize, clean, culture, store, and distribute germplasm under high scientific standards of operation, and to deal with individual requests for crop diversity from users worldwide. GHUs are specifically tasked with complying with the International Plant Protection Convention (IPPC), the multilateral treaty overseen by FAO to secure coordinated, effective action to prevent and to control the introduction and spread of pests of plants and plant products.

In her presentation Safaa Kumari, a plant virologist at the International Center for Agricultural Research in the Dry Areas, said the transboundary spread of pests and diseases has increased dramatically in recent years through international trade of infected seeds, tissue culture materials, and others. The key challenges of germplasm exchange include emerging diseases and insect pests, minor pests and diseases that are becoming important due to climate change, different standard and phytosanitary demand, and limited funding for preventive measures. 

“GHU efforts have averted the inverted spread of insects and pathogens enabling global access to global crop productivity improvement programs,” said Dr. Kumari. “The global distribution of GHUs in developing countries enabled them to play an important role as Center of Excellence in support of national or regional pest and disease surveillance and rapid response to avoid the scenario similar to the COVID-19 pandemic.”

During the roundtable discussions, featured panelists gave their key recommendations on plant germplasm health:

Mr. Mirko Montuori (project officer, FAO-IPPC)
Continuing an open dialogue among regulators, researchers, and the private sector beyond the International Year on Plant Health is important to facilitate the safe international transfers of plant germplasm

Dr. Charlotte Lusty (coordinator, CGIAR Genebank Platform)
A more sophisticated global system for germplasm health will require a multilayered system of germplasm health testing at the local, subnational, national, regional, and intercontinental levels and paying close attention to the risks at each level. GHUs and all plant health processes should organize into these layers.

Dr. Ravi Khetarpal (executive secretary, Asia Pacific Association of Agricultural Research Institution)
Germplasm can be an atom bomb if it spreads virulent pathogens. We need best practices in germplasm movement where CGIAR will work closely not only with national plant protection organizations but with IPPC, national agricultural research centers, and academia.

Francoise Petter (assistant director, European and Mediterranean Plant Protection Organization)
Research should focus on technologies for determining the health germplasm materials such as high-throughput sequencing and generic tests for detecting groups of pests; germplasm characterization for key traits linked to resistance, conservation methods that keep germplasm materials healthy, and improved sanitation methods.

Vivian Polar (senior gender and innovation specialist, CGIAR Research Program on Roots, Tubers, and Bananas)
GHU action areas can have a strong influence and can be influenced by gender and social inclusion. Germplasm and pests move through people so we need to understand the people dimension of germplasm health. Men and women have different mechanisms for exchanging plant materials. Potential areas of research and operations could include collecting social and gender data to understand the gender roles, norms, and cultures linked to germplasm management.

The event is part of a series of four webinars hosted by the CGIAR, aimed at celebrating the International Year of Plant Health. For more information on the series and to sign up for webinars 3 and 4, visit the website at