By: Matt McIntosh
Modern plant science is only the latest in a long history of innovations
The crops grown today are not as they once were. At some point in human history, we changed them.
From flowers to fruits, the number of tools we can use to select and improve plants has expanded, particularly in the last half of this century. Some plant breeding technologies are old, some are comparatively new, but they all help us adapt to challenges – from climate change and food insecurity to nutrition, taste, and food waste.
Variety selection – the first and longest-lasting technique
Plant breeding is an ancient technology, with origins after humans began domesticating wild plants – something which happened as far back as 12,000 years ago, according to National Geographic.
Picking seeds from what appeared to be the best performing plants, early agriculturalists initiated the first instances of variety selection. Over time these strains came to dominate.
Later, in the last millennia BCE, ancient peoples subsequently discovered they could also grow better plants by actively manipulating them directly. That is, selecting for specific traits they identified as beneficial – those more resistant to disease or with desirable growth characteristics, for example.
At its core, this approach to variety selection is still used by farmers and researchers around the world.
Where did it come from?
The ancestors of modern crops came from many places around the globe. Examples include:
- Wheat and barley from Mesopotamia
- Figs from Syria
- Rice from China
- Squash and corn from Mexico
- Potatoes from the Andes region of South America
Related species bring new crops
It wasn’t until the mid 18th century that we learned plants can cross-breed with related species. This revelation allowed for the development of completely new crops. The grapefruit is one such example, as explained by Ian Affleck, vice president at CropLife Canada – Canada’s national association for biotechnology and crop protection companies.
“Grapefruit didn’t exist until 1750. When someone planted an Indonesian pomelo and a Jamaican sweet orange side by side, they cross pollinated and we ended up with something new on the branch. They tried it and said ‘hey this is actually pretty good. We’re going to keep this around.’”
“We often think about some of the foods we have today as being around forever, but they’re not. They’re rather recent in the scale of human history.”
Mutations can be a good thing
The concept of genes and genetic science was still unknown in 1750 in that people had no true understanding of why they were able to successfully develop better plants. Our modern understanding of heredity and genetic traits began in 1863, though it wasn’t until 1940 that plant breeders acquired the ability to select for the unique traits held by individual plants.
“Just like humans, a plant’s genes are not comprised of 50 per cent one parent and 50 per cent from another. We’re more like 49 and 49, with two per cent being random things unique to the individual,” says Affleck.
“We call those mutations, or variations that happen when things reproduce.”
New plant varieties do not happen overnight, of course. Indeed, breeders often have to produce many generations before the desired traits are consistently expressed. But by capturing unique traits, researchers in the 20th century were able to encourage those changes to occur more quickly. The result was new varieties could be developed in less time.
Working directly with genes
1996 marked the introduction of what is commonly called GMOs (genetically modified organisms), though research on the subject began decades before. The technical term is “transgenic,” referring to a process of incorporating a section of DNA from one organism into another.
Just as the ability to manipulate crops was a major refinement for ancient people, transgenic breeding marked a major refinement for modern plant breeders. It came just in time for some crops too, including the Hawaiian papaya.
“There was a disease wiping out the papaya in Hawaii, and they couldn’t figure out how to stop it. It almost completely decimated the industry,” says Affleck, referring to the pathogen papaya ringspot virus.
“A Hawaiian university researcher figured out how to take the papaya and make it resistant to that disease. It saved the Hawaiian papaya…The papaya we buy all over the world today, 80 per cent of them are GMO based on that university researcher’s work.”
In Canada, the only transgenic plants currently cultivated are sugar beets, alfalfa, canola, soybeans, potato and seed corn (not the sweet corn we normally eat). These and any transgenic product must go through additional regulatory steps before it can be grown and sold by Canadian farmers. This process can take many years.
Getting even more precise
It wasn’t the last advance, though. Throughout the 2000s scientists began working directly with genes through lesser-known technologies – namely marker assisted breeding and genomic selection. Gene editing is another, and one which has garnered the most attention.
Gene editing gives scientists the ability to make very precise and permanent changes within an organism’s existing genetic code—changes that can be inherited by subsequent generations. This is in contrast to the transgenic approach, which incorporates useful DNA from a different genetic code. Specific apple and potato varieties are examples of gene edited crops currently being sold.
“DNA is like a long book of information,” says Affleck. “Scientists can now identify the exact page, exact paragraph, and even the exact word they want to change.”
Some gene-edited crops are already available. The potential for gene editing in both food production and medicine, however, is enormous. The United Nations Food Systems Summit’s Scientific Group, for instance, views gene editing is a key technology for ending global hunger. The organization also believes it to be a very valuable tool for both addressing and adapting to climate change.
Biotechnology as old as human civilization
Wheat varieties with less gluten for those with dietary restrictions, new coffee varieties resistant to troublesome diseases, low-bruising apples to reduce food waste – each is an example of how we’re employing science to adapt and improve plants. Today’s plant breeders in both the public and private sector continue using a wide array of tools to improve crops for end consumers and the farmers tasked with growing them.
Though the tools might change, plant breeding itself is inextricably linked to human history. Affleck reiterates it’s important to remember how much effort goes into the development of new crop varieties. Doing the research, conducting the trials, proving the variety is safe and useful, and navigating Canada’s regulatory process requires a lot of time, money, and dedication by Canada’s scientists.
“We have to remember there are people behind this. We need to celebrate the carpenter as well, not just their tools.”
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