A team of researchers led by a New Mexico State University professor crisscrossed "Sky Island" mountain ranges in southern New Mexico and Arizona this fall in search of wild tepary beans.

Richard Pratt, a professor of plant breeding and genetics in NMSU's Department of Plant and Environmental Sciences, oversaw the excursion as part of a two-year research project funded by the Agricultural Research Service, a division of the U.S. Department of Agriculture.

Pratt has studied tepary beans and other native crops for several decades.

Tepary beans are heat and drought-tolerant legumes native to the American Southwest. Although cultivated by Indigenous communities for thousands of years in ancient, irrigated cropping systems, the beans nearly went extinct in the early 20th century.

Interest in teparies has grown in recent years as researchers like Pratt seek to enhance food security by reducing water use via drought-tolerant and sustainable crops such as teparies, which need less water than other bean crops.

"Tepary beans are a vital germplasm resource for the improvement of drought and heat-stress resistance in the important economic crop Phaseolus vulgaris (common beans)," Pratt said. "Common beans are not particularly heat or drought tolerant, and they're susceptible to various diseases and pests. But scientists have already successfully transferred pest and disease resistance from tepary beans into common beans."

The process, however, requires plenty of genetic diversity – and wild species.

For decades, scientists have collected wild teparies in areas across Arizona and northern Mexico, then stored harvested seeds at the USDA National Plant Germplasm System in Washington state. Until Pratt and his colleagues stepped up in 2023, the seed bank lacked specimens from southern New Mexico.

"That's a gap the USDA seed bank would like to have us close," he said. "They would like to have all of this genetic diversity in our wild populations in seed storage."

He added: "There are two reasons to collect the wild teparies. One is for improvement of cultivated tepary beans, and the other is for improvement of common beans through interspecific hybridization."

Pratt and his colleagues started the project in 2023.

This year, the group included researchers from the Alliance of Bioversity International and the International Center for Tropical Agriculture in Colombia, as well as scientists from USDA's Agricultural Research Service, including its bean curator from Pullman, Washington, and tepary breeder from Puerto Rico. Pratt and his colleagues spent two weeks in October harvesting wild teparies in the Organ Mountains, Big Burro Mountains and the Gila National Forest in New Mexico. They also found beans in the Chiricahua Mountains in southeastern Arizona.

To prepare for the excursion, the group scouted several locations of interest, studied topographic maps and identified new populations of wild teparies. Pratt said seeds collected by the team will be propagated by the USDA to increase their quantities, then cataloged and stored in the USDA seed bank for preservation and research endeavors.

"They're put into long-term storage under ideal conditions," he said. "Researchers will be able to access and search the seeds."

The seeds will also be stored in a similar facility at the International Center for Tropical Agriculture, which houses the world's largest collection of bean germplasm. A subset of the collections will also eventually be sent to the Svalbard Global Seed Vault in Norway.

Pratt said his work may help researchers develop improved varieties of tepary beans and hybridized common beans, which could potentially increase dry bean production in the Southwest. He said New Mexico and Arizona had once been significant bean-producing states, but production in both states plummeted during the 20th century.

The full article can be seen at https://newsroom.nmsu.edu/news/nmsu-professor-leads-international-team-hunting-for-wild-tepary-beans/s/c8e44096-da20-47a0-9126-9eb7e45f595e