How it Works
The simplest definition of plant breeding is crossing two plants to produce offspring that, ideally, share the best characteristics of the two parent plants. Throughout the history of civilization, plant breeding has helped farmers solve complex challenges while also appeasing the appetites of consumers. Even the earliest farmers understood that to survive, they needed plant varieties specifically adapted to their environmental conditions and cultivated to produce the best foods to nourish their livestock and communities.
Breeding Gene by Gene
In the past, prior to genetic understanding, selective breeding was done by visually looking for plants that showed evidence of a beneficial trait such as resistance to diseases or higher yield. Detecting traits and taking notes on key characteristics of the plant is called phenotyping. With phenotypic selection, people select parent plants with traits they find valuable like flavor, texture, growth habit, and adaptability. Selections continue to improve that trait through generations of breeding. While phenomics is still used today researchers aim for the same outcome in a more precise and efficient way through analyzing the genes of a plant.
Using genotyping, we can detect differences in the DNA sequence to predict how variants will affect plant performance. This is called genotyping. Molecular breeding (also known as marker-assisted breeding) is the process of selecting a plant for its superior quality or desired traits by examining its genetics then identifying (or marking) which plants contain the same piece of DNA. DNA markers, and the precise sequence of the identified genetic information, allow scientists unique insights into creating new combinations. Today, we are working toward breeding literally gene by gene.
Advancements in both phenotyping and genotyping now play an important role in improving the sustainability of farm operations because we match the right genetics for certain cropping variables and conditions making the best use of the land, inputs, and agricultural practices.
Most of the fruits, vegetables, and grains that we eat today are the result of generations of plant breeding. In fact, some of the most popular fruits and vegetables originated from plants that would be almost unidentifiable now.
Carrots
Carrots were originally yellow and purple. In the 1600s, humans began breeding them to be white and orange. Then, in the 1700s, they were bred to be red. Purple carrots are still grown in Europe and Asia, and red carrots are grown in China and India.
Watermelons
About 5,000 years ago, watermelons measured only two inches in diameter and had a bitter taste making them vastly different from the large, sweet-tasting fruit we enjoy today.
Bananas
Humans started breeding Musa acuminate, the ancestor of the modern-day banana, about 6,500 years ago. Musa acuminate was then crossed with Musa balbisiana to produce a close cousin of the banana called plantains. Learn more about the modern banana, the fungus currently threatening bananas called Fusarium Tropical Race 4, and how plant breeding is trying save them at The History of the Modern Banana.
Corn
Humans discovered Teosinte, a plant with small, thin “cobs” only 5-8 centimeters (2-3 inches) long and kernels so hard they would crack your teeth. Over thousands of years of selection, Teosinte was adapted to produce the 30-centimeter (12-inch) ears of corn commonly grown today.
Cauliflower, Broccoli, Cabbage, Brussels Sprouts, and Kale
These common vegetables descended from the common Wild Mustard plant about 10,000 years ago.