Genetic variation gives carrots a range of different colors
Addictive Creative/Shutterstock
Origins of Orange Carrots
Orange carrots, known for their bright color and sweetness, have a fascinating history. The first domesticated carrots were purple or yellow and were grown in central Asia during the 10th century. It wasn’t until the 1400s, in western Europe, that orange carrots emerged, most likely as a result of crossbreeding yellow and white carrots.
Carrots’ Status as a Nutritious Vegetable
Orange carrots gained popularity not only for their vibrant color but also for their health benefits. The early 1900s saw a growing understanding of the medicinal properties of orange carrot juice, contributing to their status as an iconic healthy vegetable.
The Science behind Carrots’ Distinctive Color
A team of researchers, led by Massimo Iorizzo at North Carolina State University, has recently unraveled the science behind the orange color of carrots. By sequencing the genomes of 630 types of carrots, the scientists identified three specific genes that are turned off in orange carrots but turned on in purple, yellow, or white carrots.
Carotenoids and Vitamin A
These genes regulate the levels of alpha-carotene and beta-carotene, which are carotenoids – a group of pigments. In the human body, alpha and beta-carotene are converted into vitamin A. Vitamin A is crucial for maintaining the health of the eyes, immune system, and other parts of the body.
Increased Pigment Production
When these genes are switched off in orange carrots, they produce more alpha and beta-carotene pigments. This higher pigment production gives orange carrots their signature hue and makes them a rich source of vitamin A. In contrast, other carrot varieties have higher levels of different carotenoid pigments that do not convert into vitamin A.
Unintentional Selecting for Beneficial Traits
Interestingly, many orange carrots also possess gene variants that delay their flowering. Delayed flowering usually results in tougher and inedible carrots. However, it seems that farmers have been unknowingly selecting these carrots with beneficial traits for centuries.
Paving the Way for Better Carrots
With a deeper understanding of carrot genetics, Iorizzo and his team hope to utilize this knowledge to breed ever better carrot varieties in the future.
