Scientists have unlocked evolutionary secrets of landraces through an unprecedented study of allelic diversity, revealing more about the genetic basis of flowering time and how maize adapts to variable environments, according to new research published in Nature Genetics journal. The discovery opens up opportunities to explore and use landrace diversity in new ways to help breeders adapt crops to climate change and other emerging challenges to crop production.
Farmers worldwide have been ingeniously adapting landrace maize varieties to their local environments for thousands of years. In this landmark study, over 4,000 landraces from across the Americas were analyzed and their DNA characterized, using recent advances in genomics.
The CIMMYT maize germplasm bank holds 28,000 samples of unique maize genetic diversity that could hold the key to develop new varieties farmers need. Photo: Xochiquetzal Fonseca/CIMMYT.
Biodiversity is the building block of health for all species and ecosystems, and the foundation of our food system. A lack of genetic diversity within any given species can increase their susceptibility to stress factors such as diseases, pests, heat or drought as they do not have the genetic variation to respond. In the worst circumstances, this can lead to devastating consequences that include crop failures and extinction of species and plant varieties. Conserving, and utilizing, biodiversity is crucial to ensure the food security, health and livelihoods of future generations.
The 13th meeting of the Conference of the Parties (COP 13) to the Convention on Biological Diversity will be held in Cancun, Mexico from December 5 to 17, 2016. Established in 1993 due to global concerns over threats to biodiversity and species extinctions, the Convention on Biological Diversity is an international legally-binding treaty with three main objectives: the conservation of biological diversity; the sustainable use of the components of biological diversity; and the fair and equitable sharing of the benefits arising out of the utilization of genetic resources.
Trainees work with KDSmart phenotyping technology, one of the subjects taught in the new SeeD distance learning modules. Photo: G. Salinas/CIMMYT.
An online learning platform created in partnership with the Seeds of Discovery (SeeD) initiative will revolutionize the project’s capacity development efforts, allowing SeeD to reach more users than ever before.
Distance learning modules consisting of practical and theory modules about how to enhance the use of genetic diversity in wheat and maize, will allow anyone in the world to benefit from SeeD’s collection of knowledge and tools regardless of location or income. These new distance learning modules are free and will be available online to the public in the future.
SeeD works to unlock and utilize novel genetic diversity held in genebanks to accelerate the development of improved maize and wheat varieties. The initiative has generated massive amounts of invaluable information on the genetic diversity of maize and wheat, as well as cutting edge software tools to aid in its use and visualization.
“This information and tools have been made publicly available so that breeders and researchers around the world can develop improved crop varieties,” said Gilberto Salinas, head of capacity development at the SeeD initiative. “However, if people don’t know how to effectively utilize these datasets and software, the information is useless,” he said.
Maize collections held at the CIMMYT genebank in Mexico.
Public initiatives to facilitate the use of genetic resources must be promoted to demonstrate the value they add to agriculture for development and food security research, says Kevin Pixley, director of the Genetic Resources Program at the International Maize and Wheat Improvement Center (CIMMYT).
Pixley heads the Seeds of Discovery (SeeD) initiative at CIMMYT through which scientists are working to unlock novel, or new, genetic diversity held in germplasm banks – often popularly known as gene banks – to accelerate the development of maize and wheat varieties that grow better under environmental pressures like erratic weather and water scarcity, as well as provide increased nutritional value. CIMMYT scientists do this by identifying crop varieties that display valuable traits like drought and heat-stress tolerance that allow them to flourish despite these stresses.
As severe weather and evolving crop diseases threaten farmers’ livelihoods and global food security, scientists are using novel DNA tools and informatics to unearth high-value traits from vast maize and wheat seed collections, for use in breeding climate-resilient varieties to feed the future.
By Jennifer Johnson, Terry Molnar and Martha Willcox
Felix Corzo Jimenez , a farmer in Chiapas, Mexico, examines one of his many maize plants infected with tar spot complex.
In southern Mexico and Central America a fungal maize disease known as tar spot complex (TSC) is decimating yields, threatening local food security and livelihoods. In El Portillo, Chiapas, Mexico, local farmer Felix Corzo Jimenez surveys his maize field sadly… “It’s been a terrible year. We’ll be lucky if we harvest even 50 percent of our usual yields.” He fingers a dried up maize leaf covered in tiny black dots, and pulls the husk off of an ear to show the shriveled kernels, poorly filled-in. “Tar spot is ruining our crops.”
Named for the telltale black spots that cover infected plants, TSC causes leaves to die prematurely, weakening the plant and preventing the ears from developing fully, cutting yields by up to 50 percent or more in extreme cases. Caused by a combination of 3 fungal infections, the disease occurs most often in cool and humid areas across southern Mexico, Central America and into South America. The disease is beginning to spread, possibly due to climate change, evolving pathogens and susceptible maize varieties, and was reported in important maize producing regions of central Mexico and the northern United States for the first time last fall. To develop the TSC resistant maize varieties that farmers need, the Seeds of Discovery (SeeD) initiative is working to “mine” the CIMMYT genebank for native maize varieties that may hold genes for resistance against the disease.
The CIMMYT germplasm bank is the lifeblood of many Seeds of Discovery (SeeD) activities, preserving the genetic diversity that is necessary to develop improved maize and wheat varieties with novel genetic variation to feed a growing population in a changing environment.
The bank contains over 170,000 wheat and 28,000 maize seed collections from across the world. These collections represent the genetic diversity of unique native varieties and wild relatives of maize and wheat and are held under long-term storage for the benefit of humanity in accordance with the 2007 International Treaty on Plant Genetic Resources for Food and Agriculture. The collections are also studied and used as a source of diversity to breed for crucial traits such as heat and drought tolerance, resistance to crop diseases and pests, grain yield productivity and grain quality. Seed is freely shared on request to researchers, students, and academic and development institutions worldwide.
To learn more about the history of the CIMMYT germplasm bank, as well as their recent activities and accomplishments, please click here:
If you have ever received seed from the CIMMYT maize germplasm bank, please fill out their customer follow-up survey for the maize germplasm bank here and the wheat germplasm bank here
Calling all post-graduate students interested in genetic diversity! Graduate students working with The International Maize and Wheat Improvement Center (CIMMYT) will be holding an international symposium, “Genetic Diversity: The key to modern crop improvement and food security,” at CIMMYT headquarters in Texcoco, Mexico on 25 and 26 August. The symposium is open to post-graduate students interested in plant breeding and genetic diversity, and will be held in both Spanish and English with simultaneous translation available.
This event is part of the DuPont Plant Sciences Symposia series, established in 2008, and is one of nearly 20 DuPont Pioneer symposia that will be held this year across the world. Organized for, and by postgraduate students, these symposia allow student organizers to gain valuable skills and experience in event organization. The students are organizing this event with the support of by Gilberto Salinas, head of capacity Development at the Seeds of Discovery (SeeD) initiative, and Tabare Abadie, lead of Research Effectiveness at DuPont Pioneer.
By Mike Listman
Sukhwinder Singh at a field of Punjab Agricultural University, India, with Mexican wheat landrace evaluation trial (foreground) and wheat lines derived from the landraces (background). Photo: Mike Listman
For the first time ever, a research team from China, India, Mexico, Uruguay, and the USA has genetically characterized a collection of 8,400 centuries-old Mexican wheat landraces adapted to varied and sometimes extreme conditions, offering a treasure trove of potential genes to combat wheat’s climate-vulnerability.
Reported today in Nature Scientific Reports and led by scientists from the Seeds of Discovery project (SeeD) at the Mexico-based International Maize and Wheat Improvement Center (CIMMYT), the study details critical genetic information about Mexican landraces for use in breeding to boost global wheat productivity.
This is essential, given the well-documented climate effects that imperil key wheat-growing areas, according to scientist Sukhwinder-Singh, SeeD wheat researcher at CIMMYT and corresponding author for the study.
“The landraces, known as Creole wheats, were brought to Mexico as early as the 16th Century,” said Sukhwinder-Singh, who also credited the study to MasAgro, a long-term rural development project between Mexico’s Ministry of Agriculture (SAGARPA) and CIMMYT. “Wheat is not native to Mexico, but this gave the Creoles time to toughen in zones where late-season temperatures can hit highs of 40 degrees Centigrade (104 degrees Fahrenheit).”
Heat can wreak havoc with wheat’s ability to produce plump, well-filled grains. Research has shown that wheat yields plummet 6 percent for each 1-degree-Centigrade rise in temperature, and that warming is already holding back yield gains in wheat-growing mega-regions such as South Asia, home to more than 300 million undernourished people and whose inhabitants consume over 100 million tons of wheat each year.
“Typically, massive seed collections constitute ‘black boxes’ that scientists have long believed to harbor useful diversity but whose treasures have remained scarcely utilized, mostly because we have limited information about them,” explains Prashant Vikram, CIMMYT scientist and first author of the report. “New technologies are helping us to shine a light in the dark corners. As part of MasAgro’s ‘Seeds of Discovery Component,’ the team used the latest genotyping-by-sequencing technology and created unique sets of the landrace collections that together capture nearly 90 percent of the rare gene variants, known as ‘alleles.’”
By Katie Lutz
After wheat seeds are planted in the greenhouse, the samples are then harvested and prepared to be sent to the laboratory for DNA extraction and genotyping.
Photographer: CIMMYT/Carolina Sansaloni
With Syria torn apart by civil war, a team of scientists in Mexico and Morocco are rushing to save a vital sample of wheat’s ancient and massive genetic diversity, sealed in seed collections of an international research center formerly based in Aleppo but forced to leave during 2012-13.
The researchers are restoring and genetically characterizing more than 30,000 unique seed collections of wheat from the Syrian genebank of the International Center for Agricultural Research in the Dry Areas (ICARDA), which has relocated its headquarters to Beirut, Lebanon, and backed up its 150,000 collections of barley, fava bean, lentil and wheat seed with partners and in the Global Seed Vault at Svalbard, Norway.
In March 2015, scientists at ICARDA were awarded The Gregor Mendel Foundation Innovation Prize for their courage in securing and preserving their seed collections at Svalbard, by continuing work and keeping the genebank operational in Syria even amidst war.
“With war raging in Syria, this project is incredibly important,” said Carolina Sansaloni, genotyping and DNA sequencing specialist with the Seeds of Discovery (SeeD) project at the Mexico-based International Maize and Wheat Improvement Center (CIMMYT), which is leading work to analyze the samples and locate genes for breeding high-yield, climate resilient wheats. “It would be amazing if we could be just a small part of reintroducing varieties that have been lost in war-torn regions.”