Made by Aliens!? The Mystery of “Corn” That Can’t Reproduce on Its Own, and a New Variety Set to Debut in ’25 to Save Us from a Food Crisis
Developed by Aliens? The Mystery of Why It Can’t Reproduce on Its Own
Corn is a familiar sight on our dinner tables. In fact, this plant has a structure that is extremely rare among wild plants. It lacks the mechanism to disperse seeds like a dandelion; the kernels are firmly attached to the cob, and the entire female ear is enclosed by bracts, making it difficult for the seeds to disperse naturally even after maturity.Unless humans harvest and sow the seeds, it is extremely difficult for the species to perpetuate itself under natural conditions.
Given its unnatural appearance—which makes it seem as though it were created from the very beginning “to be eaten by humans”—some have even whispered that “perhaps it was a food source bestowed upon ancient people by aliens,” but
“I believe this is because humans selected and improved it to make it easier to use,”
says Associate Professor Takayoshi Ishii of Tottori University, who focuses his research on cellular diversification through interspecific hybridization.
“Many wild plants shed their seeds once the flowers bloom and the fruit ripens. They do this to scatter seeds on the ground and increase their offspring. However, since we want to eat the fruit, we can’t do that if the seeds fall off. So, we select plants that don’t drop their fruit, cultivate them, and further improve them,” explains Associate Professor Ishii (hereinafter the same).
Even corn—which was once thought to have “come from outer space”—has been shown through recent DNA research to be descended from a group of closely related wild plants in the grass family known as “teosinte.”
The domestication of corn began around 7,000 to 9,000 B.C. The earliest corn had very small ears, but it is said that through thousands of years of selecting plants that produced larger ears and planting those seeds, corn evolved into the form we know today.
“Plants in the nightshade family contain toxins, but the tomatoes and eggplants we eat today come from plants with low levels of toxins in their edible parts. This is because we have selected and cultivated strains with lower toxicity. This is how humans have improved plants.”
Chinese Cabbage × Cabbage = “Hakuran”
Crops are not solely the result of human selection. New species can also arise through natural hybridization. Take bread wheat, for example, which is used to make bread.
“Bread wheat is the result of natural cross-pollination between tartary wheat—which likely grew in the same fields as cultivated varieties similar to durum wheat, used in pasta—and other plants. Because it was highly valuable to humans, it came to be cultivated all over the world.”
Generally, crossbreeding involves combining individuals of the same species or variety to create new traits. Many crops have been improved through hybridization, and today we can see crops in a wide variety of shapes and colors.
In 1959, Sadao Nishi developed “Hakuran,” a hybrid of Chinese cabbage and cabbage. It is a pioneering success story of an interspecific hybrid within the Brassica genus, created using embryo culture to cultivate hybrid embryos.
“While people enjoy the crisp texture of cabbage, I think Chinese cabbage is more often used in hot pots or made into kimchi, where its softer, more mellow flavor is appreciated. Its appearance is somewhere between Chinese cabbage and regular cabbage. It’s delicious whether eaten raw, cooked, or pickled.”
In addition, there was reportedly a variety called “Oretachi” created by crossing an orange with a bitter orange.
“Generally, hybridization is achieved by artificially pollinating the stamens and pistils, but ‘Oretachi’ was developed as a ‘cell fusion’ (somatic hybrid) using protoplasts—plant cells from oranges and karatachi with their cell walls removed.While it is possible to culture hybrid embryos and regenerate plants after distant crossbreeding in the grass family, somatic hybrids are extremely difficult to produce.”
Born in ’25! A New Variety to Save Us from the Food Crisis
In ’25, a research group led by Associate Professor Ishii became the first in the world to create “corn-wheat” by fusing any number of corn and wheat egg and sperm cells under a microscope. So, what kind of plant did they end up with?
“It looks like wheat. When cross-pollinated, the maize-derived nuclear genome was lost after fertilization. That’s why it looks like wheat. On the other hand, the mitochondrial genome—which functions as an energy producer and environmental sensor—had become a hybrid genome of wheat and maize.”
When we planted this “corn-wheat”—with its hybrid mitochondrial genome—in the fields of the Arid Land Research Center and conducted experiments,
“Some of them grew larger, and others produced higher yields. While there are currently concerns about a food crisis due to conflicts and extreme weather, corn undergoes C4 photosynthesis. Plants that perform this type of photosynthesis have high water-use efficiency and photosynthetic efficiency, making them crops capable of producing higher yields with limited water and resources.”
I hope that through continued breeding, we can eventually develop a wheat variety with the characteristics of corn. However, this is not something that can be achieved in just a few years—it may take decades, or perhaps it won’t happen in my lifetime. Even so, we have established the technology to create something the world has never seen before. I think it would be wonderful if we could achieve interspecific hybridization adapted to various environments around the globe.”
Long ago, it took people thousands of years to develop corn from a plant called teosinte. Now, using the latest technology, we are trying to create plants that have never existed before. Will we end up with something that looks like it was brought here by aliens?
▼ Takayoshi Ishii: Associate Professor at the International Research and Education Organization for Arid Lands, Tottori University. He develops crops resistant to various stresses, such as drought, using cell engineering and chromosome engineering techniques. In 2025, he succeeded in creating a wheat-maize hybrid plant in collaboration with Professor Ryuji Okamoto of Tokyo Metropolitan University and Associate Professor Ryosuke Tsuma of Kobe University.
Reporting and Text： Izumi Nakagawa PHOTO： Afro