A team from the Agricultural Genomics Institute in Shenzhen and the Chinese Academy of Agricultural Sciences in the Chinese mainland, alongside Lanzhou University and partners in Canada and the U.K., has uncovered a botanical surprise: the humble potato owes its origin to an ancient cross with the tomato.
Published this month in Cell, the study dives into 101 genomes and 349 re-sequenced samples from cultivated potatoes and their 56 wild relatives. The genetic detective work revealed that roughly 9 million years ago, a potato-like plant called Etuberosum mated with an ancestral tomato. This genetic fusion didn't just merge DNA; it accidentally created a brand-new plant organ: the tuber.
Native to South America, the spud has traveled the globe—its high nutritional value and adaptability inspiring everything from comfort food to a classic condiment pun.
According to lead researcher Huang Sanwen, the tomato served as the maternal parent of the potato, while Etuberosum was the paternal parent. Key genes for tuber formation also split between the parents: SP6A from the tomato side flips the switch for tuber initiation, and IT1 from Etuberosum controls tuber stem growth; only together do they trigger tuber development.
But why did only potatoes evolve tubers? The team suggests that after hybridization, genes from both parents reshuffled to form a new organ—the tuber—which stores water and starch underground. This gave potatoes a survival edge, allowing them to withstand drought, cold, and reproduce vegetatively.
Today, potatoes thrive from South American highlands to alpine meadows worldwide, thanks to a mosaic of parental genes that helps them adapt to diverse climates. Beyond rewriting the potato’s family tree, these findings open doors for next-generation breeding, aiming to boost yield and resilience in a warming world.
This discovery not only deepens our understanding of plant evolution but also sparks fresh ideas for global food security and sustainable agriculture.
Reference(s):
cgtn.com
