In Brazil, corn is present in practically everything: in crops, in feed, in industry and on Brazilians’ plates. But behind the abundance of this grain, there is an effort to ensure that it continues to exist, even in the face of pests, diseases and climate change.
In Sete Lagoas (MG), Embrapa Milho e Sorgo maintains the Active Germplasm Bank (BAG-Milho), one of the main genetic conservation structures in Latin America. The site is home to 3,886 varieties of corn (Zea mays L) and 7 from wild relative species, such as Mexican zea e Tripacum dactyloidesstored in cold rooms between 6°C and 8°C and controlled humidity of 25% to 30%.
In practice, it is one that protects the genetic diversity of corn, one of the most important cereals in the world.
Why corn needs to be protected
According to Embrapa, modern production is based on a few highly productive varieties, which increases productivity, but also brings risks. The genetic uniformity of current cultivars makes plantations more vulnerable to pests and diseases, explains the organization’s study.
The study also points out that landraces and wild varieties, on the other hand, carry resistance and environmental adaptation genes, essential characteristics for the development of new cultivars in contexts of climate crisis. Preserving these seeds is a way of guaranteeing the future of the crop and the future.
This type of conservation is called “ex situ”, that is, carried out outside the plant’s natural environment, and is considered the safest and most economical method for preserving the genetic diversity of a species.
How the bank works
According to Embrapa, each variety stored at BAG-Milho is treated as a genetic heritage. They are characterized and evaluated based on 32 agronomic descriptors, such as plant height, ear size and shape, grain color, number of leaves and disease resistance.
When the stock of a variety becomes small (less than 1 kg of seeds) or germination drops below 80%, the material is regenerated in the field.
After harvesting, the seeds undergo screening, drying and laboratory tests. They are then stored again in cold chambers, in cotton bags, and monitored every five years to check humidity and viability.
Results and advances
According to Embrapa, even with limitations, the results of BAG-Milho are significant. Between 1994 and 2003, an average of 188 varieties were characterized or regenerated per year. In 1998 and 1999, the bank repatriated 1,371 samples collected in Brazil in the 1950s and kept in Mexico, expanding the diversity of the national collection.
Monitoring carried out in 1999, with seeds stored since 1980, showed that 88.4% of the samples maintained germination equal to or greater than 85% after 18 years of conservationan index considered to be of global excellence.
Today, 100% of the collection is documentedand around 60% of the accessions have already been regenerated and characterized. Each seed represents a set of genetic information that can contribute to the development of more resistant and productive cultivars.
A scientific and cultural heritage
The Active Corn Germplasm Bank is also a cultural preservation initiative. The Creole seeds stored there represent traditional knowledge of farmers and indigenous people, who cultivated corn in ways adapted to their regions and histories. Preserving these varieties means protecting food identity, biological diversity and scientific sovereignty.
