Carrot history
This time I would like to talk about carrots. About the ever-present orange one, but also about the white, yellow, and purple variants. A group of American and Polish researchers resequenced the genome of 630 carrot variants. Through doing this they deciphered a lot about its history and its orange colour.
Wild carrots are often white in colour. Studying the 630 carrot genomes suggest that between 15 thousand and 10.8 thousand years ago in Asia the first steps of carrot domestication took place. Around that time the first purple and yellow carrots appeared on stage. Other signs of domestication is the selection for late flowering. This allowed the carrots to stay juicy.
While the deep orange colour only reveals itself when there are only recessive versions present
2.8 to 2 thousand years ago with the arrival in Europe a second split between eastern and western carrots took place. Whit the western carrots the precursors of the orange carrot. Although these themselves were not yet orange. Only in 1500 breeders started selecting on purpose for the orange colour.
After genetic analysis the researchers observed three genes to be responsible for the orange colour. Two of those where previously known: Or1 and EX1. But the researchers discovered a third: REC1. Having more dominant versions of these three genes result in a paler carrot. While the deep orange colour only reveals itself when there are only recessive versions present.
One last fun fact, this research supports the suggestion that the orange selection probably started in the Netherlands. Even though the orange carrot is a relative newcomer, it is one of the most popular of the family.
Literature
Coe, K., Bostan, H., Rolling, W. et al. Population genomics identifies genetic signatures of carrot domestication and improvement and uncovers the origin of high-carotenoid orange carrots. Nat. Plants (2023). https://doi.org/10.1038/s41477-023-01526-6
Plant en Zo 