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.
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