Hop in the DeLorean, crank up the flux capacitor, and set the date and location to around 8,000 BC in the Andean mountains where you’ll find the ancestor of today’s modern peanut. Witnessing the birth of the peanut sounds totally amazing, but what would really have you saying “great Scott” is realizing that the peanuts we eat today are virtually unchanged from their original ancestor. We don’t have time travel technology, but a team of peanut researchers were able to unearth the static history of the 10,000-year-old peanut while mapping the peanut genome. Their research may help further peanut sustainability.
The U.S. peanut industry came together several years ago to establish the Peanut Genome Project, an extension of the International Peanut Genome Initiative. Their goal was to map the genetic make-up of peanuts to improve disease, pest, and environmental stress resistance through marker-assisted breeding without using GMO technology. Yes, that’s a mouth-full of Dr. Emmett Brown lingo, so let’s put it into layman’s terms.
The birds and the bees of plant breeding
Humans have practiced traditional plant breeding since crops were first cultivated. In recent years, that process has improved modern agriculture by producing crops with the most desirable traits, such as the ability to grow in dry climates, or bear more fruit. Think of those county fairs with various types of beautiful produce on display and up for an award. The seeds from those blue-ribbon winning fruits and vegetables yield equally prize-worthy produce.
Peanut researchers have used traditional breeding to make peanut production more efficient, and sustainable. Today’s peanut varieties yield more than they did a decade ago, and peanut farmers use less energy, water and inputs than in the past. Unfortunately, identifying the beneficial traits of peanuts using traditional breeding takes a long time because researchers have yet to pinpoint exactly which genetic codes contribute to those desirable results. That is, until now. Stay with me, because we are about to ditch the DeLorean and hop into Ms. Frizzle’s magic school bus.
The pair of genes that led to peanuts
Scientists have long speculated that the genetic material in cultivated peanut (Arachis hypogaea) is a hybrid derived from two separate plant species, Arachis duranensis (a native herb in the Andean mountains) and Arachis ipaensis (a cousin of the modern peanut). They believe that early inhabitants of South America brought A. ipaensis into the area where A. duranensis was naturally growing, and the two species cross-pollinated to create peanuts. As a result, peanuts inherited chromosomes from both of these plant species. Mapping the peanut genome, therefore, meant that scientists first needed to map these two “parent” species. Complicating that process was the fact that until recently, scientists thought A. ipaensis was extinct.
All of that changed when researchers from the University of Georgia discovered that A. ipaensis was alive and well and growing in Bolivia. Not only were they able to confirm that A. duranensis and A. ipaensis were in fact the original species that gave birth to the peanut, but they also discovered through mapping the DNA of those species, that peanuts today remain 99.96 percent identical to their ancient progenitor.
Having found the missing link in the peanut puzzle, researchers with the Peanut Genome Project have now mapped the DNA of these two species, giving them a better picture of the overall peanut genome. Eventually, they hope to use this map to pinpoint genetic traits in peanuts using marker-assisted breeding that will lead to even more sustainable varieties. If they can locate genetic traits that make peanuts more resistant to disease or even drought, then they can breed varieties with those natural genetic advantages to reduce inputs and further improve yields. They may even find genetic traits that can enhance the nutrition profile of peanuts, adding to their already healthy halo.
Thanks to the peanut industry, researchers at the Peanut Genome Project, and members of the International Peanut Genome Initiative, the future of peanuts looks even more promising for farmers, consumers, and the environment. But even though they’ve come a long way and have spanned the globe, they’re still a spitting image of their 10,000-year-old ancestor.
Photo courtesy of Merrit Melancon/University of Georgia