It is common for people who support or defend genetically modified foods (GMOs) to argue something along the lines of, “What’s the big deal? Humans have been genetically modifying plants for thousands of years.”
Unfortunately, this claim can only be made by someone who either doesn’t understand seed breeding, or who is outright trying to deceive you. Here’s why…
Today, seeds are bred in only one of three ways: 1) in an open pollinated environment, 2) through a hybrid cross, and 3) through genetic modification. Let’s look at each, one at a time.
What are Open Pollinated Seeds?
Open pollinated (OP) seeds are seeds that are produced from natural, random, open pollination by wind, birds or insects, resulting in plants that are naturally varied.
Open pollinated seed saving is the oldest of the three methods of producing seed. Gardeners and farmers have been carefully selecting open pollinated seed varieties that have beneficial traits (like drought tolerance or good flavor) for as long as we have been doing agriculture. Almost all heirloom seeds are open pollinated.
When a gardener or seed breeder raises open pollinated plants, she has to keep pollen from other related varieties from entering the patch (generally accomplished with distance from the other variety).
If successful at keeping the open pollinated variety isolated, she or he will be able to select and save seeds from the very best plants in the patch, and trust that they will grow out next season with the same characteristics as their parent plant.
This is how most of the sweet, juicy, large fruits and vegetables we enjoy today (like corn, potatoes and squash) were bred and selected over many generations from their bitter, small, barely edible ancestors.
What are Hybrid Seeds?
Open Pollinated Seeds Vs Hybrids
The term “hybrid,” which you’ll often see in seed catalogs, refers to a plant variety developed through a specific, controlled cross of two parent plants. Hybrids are often spontaneously and randomly created in nature when open-pollinated plants are naturally cross-pollinated with other related varieties; plant breeders just direct the process to control the outcome.
The advantage of growing hybrid seed compared to inbred, open-pollinated lines comes from the ability to cross the genetic materials of two different, but related plants to produce new, desirable traits that can’t be produced through inbreeding two of the same plants.
For example, most of today’s livestock and companion animals were created through crossing different breeds to create hybrids—from Guernsey cows to hairless cats to the Labra-Doodle!
A whole new world of food crops became available as a result of hybridization, including Canola, grapefruit, sweet corn, canteloupes, seedless watermelons, “burpless” cucumbers, as well as tangelos, clementines, apriums, pluots and other unique foods.
In fact, in addition to edible novelties, today’s methods of hybridization are helping us breed all sorts of drought and pest tolerant plants that are helping us survive and adapt to a changing climate.
Hybrids have another advantage too. Developing a non-hybrid, open-pollinated variety using classic plant-inbreeding methods can take six to ten generations. That’s a lot of time!
However, using the method of controlled genetic crossing devised by Charles Darwin and Gregor Mendel in the mid-19th century (Remember those Mendel Box genetic tables from high school biology?), plant breeders can now produce hybrid seed that combines the desired traits of two pure parent lines in the first generation.
The oldest and simplest form of plant hybridization is corn detasseling. In this method, three rows of the father breed of corn are planted, and then one row of the mother, and over and over. The mother rows are detasseled (have their pollen removed) ensuring that any pollen they receive comes only from the father rows. The mother’s seeds can then be harvested as what is known as an F1 (first generation) hybrid.
Most hybrid seeds today are created in this low-tech, low-cost way, usually under row covers in isolated fields or in greenhouses.
There is another major distinction between open pollinated and hybrid seeds: If you grow out an open pollinated seed variety, keep it well isolated, and save it for seed, you will get offspring that are very similar to the parents. But, if you purchase an F1 hybrid and you save it for seed, and then attempt to grow it out, the next generation (F2) will be a very random mix of the parents DNA, and all the plants will be wildly different.
This means you can save open pollinated seeds, adapt them for your area over many growing seasons, and enjoy caring for the plants through their entire life cycle as they produce for you from generation to generation. But, if you grow an F1 hybrid seed and you like it, you must go back to the source you got it from if you wish to grow it out again.
Big seed companies like F1 hybrids because the process gives them proprietary ownership of each new variety. And because seed from F1 hybrid plants won’t produce uniform offspring, gardeners must purchase new seeds each year.