Every superhero has their origin story. It’s the story of how it all started – how they came to be a superhero. Spider-Man was bitten by a radioactive spider. Captain Marvel absorbed the energy of the Tesseract. The Flash inhaled hard water vapors and then got his powers when a lightening bolt hit his lab. Wonder Woman is an Amazon and was granted her powers by the Greek gods.
In agriculture, we can look at crops that we grow as superheros of sorts. Each one has its own origin story too. They aren’t as fanciful or dramatic as many of our graphic novel and comic book heroes. But they are just as amazing! Consider the following.
Superhero: Corn. Secret Identity: Zea Mays or Maize. Nearly 9,000 years ago a grass in Mesoamerica – what is now Mexico – was recognized as having food potential and it was domesticated. This annual grass, teosinte, had a small seed head with 8-20 seeds. The seeds were harvested and became a staple in the diet of the indigenous people. Early farmers collected the seed heads that had the most seeds and planted those again the following year. Do this over and over again for 9,000 years and the seed head evolves from 8-20 seeds to 600-800 seeds! And along the way natural mutations (no radioactive spider or bolt of lightening required) changed those seeds. Natural mutations created blue corn, white corn, sweet corn, and popcorn. For popcorn, the natural mutation was a thick, hard exterior coating on each of the seeds. The hard exterior coating keeps moisture locked in. Then when it is exposed to heat and the moisture turns to steam, the popcorn POPS open! Sweet corn, too, is a natural mutation of the original.
Teosinte can still be found throughout modern Mexico. It looks so different from modern corn that scientists had no clue they were related. But when a DNA analysis was conducted, low and behold, they were related. Teosinte found today is the crop wild relative of modern corn.
Superhero: Wild mustard. Secret Identity: Brassica oleracea. This one little plant – wild mustard – has given rise to a number of different agricultural crops that take up a huge section in modern grocery stores. Take a look at broccoli, cauliflower, cabbage, kale, kohlrabi, and Brussels sprouts and you are basically looking at the same plant! Farmers began noticing that some wild mustard plants had very pronounced flowers or florets. They began cultivating those variety and after hundreds of successive generations we now have broccoli and cauliflower. Farmers noticed that some of those same mustard plants had large leaves. They began selecting for those traits and pretty soon – viola! Cabbage! And kale! Some of those same mustard plants had lateral leaf buds. A few generations later – and Brussels sprouts! Some of those same mustard plants had lateral meristems – and boom! Kohlrabi.
None of this happened overnight. And again, no Tesseract needed. But through careful selection of traits, farmers were able to create multiple different varieties of crops all from the same parent species. Wild mustard species still abound across Europe, Asia, and North America. It is amazing to think that these wild relatives could, through careful cultivation, someday line grocery store shelves.
Superhero: Wheat. Secret Identity: Triticum. About 500,000 years ago, two species of wild grasses crossed – long before humans entered the picture. Humans in the Fertile Crescent (what is now modern Iraq, Israel, Palestine, Syria, Lebanon, Egypt, Jordan, Turkey, and Iran) domesticated this grass. It is what we now call emmer wheat. Either on purpose or accidentally and around the time that humans began cultivating the wheat, a third wild grass joined into the mix. Because of this, wheat, as we know it today, has three pairs of every chromosome (most species only have two pairs). This gives wheat approximately 16,000 base pairs in its genome. Talk about a powerful genome! For comparison, the human genome only has around 3,000 base pairs. Wheat has long been a staple crop around the globe. It provides many of the calories needed for societies to thrive. Its complicated genetic history makes it harder for scientists to figure out but gives it a lot of diversity and potential, too. Emmer wheat is still grown today. And as a grass, modern wheat has a lot of relatives that can be found in the wild.
Superhero: Banana. Secret Identity: Cavendish. There are more than a thousand varieties of bananas throughout the world. But the type of banana that is most often consumed is the Cavendish. This variety doesn’t produce any seeds. The tiny black specs that you might find in some Cavendish are the remnants of seeds that never matured. Because of the way the Cavendish flowers it really can’t get pollinated to produce seeds. The flower grows upside down and the female parts of the flower all mature and start to form fruit before the male part of the flower even opens. This is great for consumers because they don’t have to contend with seeds. They can just peel the banana and eat the whole thing. But for farmers, without seeds, no new plants. But new plants are grown through asexual propagation. That’s right, most bananas are clones of each other! Talk about a superpower! Duplicating yourself into countless copies!
Wild banana relatives are able to sexually propagate and so bananas in the wild will have seeds inside of them with very little fruit. One benefit of identifying, knowing, and studying crop wild relatives (like wild bananas) is to tap into the power of diverse genes. The banana variety that we consumed before the Cavendish was the Gros Michel. A virulent Panamanian disease decimated the banana industry in the 1940s. Farmers had to stop growing the Gros Michel and switch to the Cavendish. Another disease is now threatening the Cavendish. By studying the wild relatives, scientists might find a gene that is resistant to the fungal disease and introduce it to save the Cavendish.
Superhero: Sunflower. Secret Identity: Helianthus. This versatile crop is widely known in Kansas (home of another super hero – Superman). But sunflowers are grown in a lot of states – either for oil or for confectionery (direct seed consumption). The seeds can be crushed to extract their oil. Or the seeds can be whole, ground, roasted, or processed in many other ways to be eaten.
“Plants are regularly challenged by a variety of environmental stresses such as drought, flooding, salt, and low-nutrient levels that negatively affect plant growth and reduce productivity. Though wild plants have evolved mechanisms to meet these challenges, many crops are less resilient. To reduce stress-induced yield loss and improve food security, attention has increasingly turned to the tapping of genetic diversity in crop wild relatives. Sunflower is an ideal crop for such an approach because the productivity of this oilseed crop is clearly limited by such stresses, while wild relative species are adapted to a variety of extreme environments,” from here.
The resulting stress-resistant cultivars could help stabilize production in developing countries in the face of environmental stresses.
Superhero: Carrot. Secret Identity: Daucus carota. Domestic carrots are so diverse that they could be seen to have many different superpowers as compared to their wild cousins. Carrots can come in a variety of colors – white, yellow, purple, and yes, orange. Compare these multi-colored carrots side-by-side in a taste test and you will likely determine that the orange ones are the sweetest. And that might be why you will usually only see orange carrots in the grocery store. Carrots have a number of relatives including the ornamental Queen Anne’s lace flower. Carrots are another great example of selective breeding practices that farmers used over countless generations. The original carrot was a scrawny, spindly, root that probably didn’t have much value. But like a superhero paired with a mentor, the carrot and the farmer grew together. The carrot developed a long tap root to store sugars. The orange color meant it was packed with vitamin A and a healthy part of the human diet. These modern carrots are definitely a superhero as compared to their wild relatives.
Every modern day crop has a back story. And most still have crop wild relatives. What crop wild relatives are you familiar with?