The International Maize and Wheat Improvement Center (CIMMYT) maize germplasm bank serves as a backup for farmers and researchers in times of catastrophic seed loss by safeguarding maize genetic diversity, a crucial building block in global food security. CIMMYT also trains local and national seed bank staff in best practices to preserve maize genetic diversity.

Natural disasters can have a dramatic impact on crop genetic diversity, threatening local and global food security. When Hurricane Stan swept through Guatemala in 2005, leading to 1,500 deaths, many farmers lost entire crops. Some indigenous communities were unable to harvest seed from their traditional maize varieties, known as landraces.

Generations of selection by farmers under local conditions had endowed these varieties with resistance to drought, heat, local pests and diseases.

As the country struggled to rebuild and replant, it was found that the entire maize seed collection at Guatemala’s national seed bank had been damaged by humidity that made the seeds vulnerable to insects and fungus and could not be replanted.

In 2016, drawing upon the back-up seed stores in its maize germplasm bank in Mexico, CIMMYT sent Guatemalan collaborators seed of more than 700 native Guatemalan maize varieties, including some of the varieties that had been lost.

Guatemalan scientists are now planting seed from the historic CIMMYT samples to ensure the varieties will grow well under local conditions. The best materials will be returned to local and national seedbanks in Guatemala, where they will be available for farmers and researchers to grow, study and use in breeding programs.

The effective conservation of seeds in the genebank outside their natural habitat is complex and costly, according to Denise Costich, head of the maize germplasm bank at CIMMYT.

“Seeds must be stored at constant low temperatures and humidity,” Costich said. “Seed bank curators must also regularly monitor the seed’s ability to germinate and, when a sample’s capacity falls too low, grow out the healthy seed in controlled plantings at a location similar to the environment of origin of the collection.”

Given the challenges and resource constraints faced by many countries with important native maize collections, international seed banks play a vital role as “safe deposit boxes for the world,” she said.

In addition to natural disasters, civil wars can also impact genetic diversity as people are forced to flee their homes, leaving seed of their traditional crops behind.

“Many believe that seed banks are needed only in the case of an “Armageddon” – some sort of global disaster that would completely disrupt agriculture as we know it,” Costich said. “But vulnerable smallholder farmers may face several ‘mini-Armageddons’ in a lifetime, crises that cost them entire crops, and with that, the loss of traditional seed varieties. If such seed is not safely stored elsewhere, then the matchless diversity it represents is forever lost to humanity.”

CIMMYT’s maize germplasm bank team based at headquarters in Mexico conserves, studies and shares some 28,000 unique collections of seed of native maize varieties and wild relatives for the benefit of humanity in accordance with the 2007 International Treaty on Plant Genetic Resources for Food and Agriculture.