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 in order 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.

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, and is a technique still used today. With phenotypic selection, people select parent plants with traits they find valuable, like flavor, texture, growth habit, adaptability, and continue to select and 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 in order to predict how these 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 and identifying (or marking) which plants contain the same piece of DNA. DNA markers, and the precise sequence of the identified genetic information, allow breeders 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 are able to 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

Originally, carrots were yellow and purple. In the 1600s, humans began breeding them to be white and orange, and 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 were only two inches in diameter and had a bitter taste, vastly different from the large, sweet-tasting fruit we enjoy today.

Bananas

About 6,500 years ago, humans started breeding Musa acuminate, the ancestor of the modern-day banana. Musa acuminate was then crossed with Musa balbisiana to produce plantains, a close cousin of the banana. Learn more about the modern banana, Fusarium Tropical Race 4 – the fungus currently threating bananas, and how plant breeding is trying save them at The History of the Modern Banana.

Corn

About 10,000 years ago, humans discovered Teosinte, which was a plant with small, thin “cobs” only 5-8 centimeters (2-3 inches) long with 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 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.