Sensory experiences highlight a vast contrast between crispy Friday night chips and succulent Mediterranean tomatoes. Nevertheless, scientific findings reveal a surprising proximity between these two seemingly disparate foods. Groundbreaking research indicates that the potato originated from a tomato ancestor almost 9 million years ago.
In the Andes, wild tomatoes interbred with a plant known as Etuberosum. Through a process termed hybridization, their genetic material combined, giving rise to an entirely new lineage. Sanwen Huang, a professor and lead researcher at the Agricultural Genomics Institute in Shenzhen, China, explained, “The tomato serves as the mother, and Etuberosum as the father.” He added, “However, this connection wasn’t initially apparent.”
When observed above ground, potato plants bear a striking resemblance to Etuberosum. Yet, once unearthed, a clear distinction emerges: Etuberosum possesses slender subterranean stems but lacks the starchy tubers that render potatoes a global dietary staple. Scientists investigated the tomato to understand the origins of these tubers. Despite its inability to produce tubers, the tomato exhibits a remarkably similar genetic makeup. Huang noted, “While they belong to the same plant family as eggplant and tobacco, the tomato, potato, and Etuberosum are genetically the most closely related.” He continued, “Therefore, we chose to examine them in greater detail.”
The research, documented in Cell, involved the analysis of 450 genomes from cultivated potatoes and 56 from wild species. According to lead author Zhiyang Zhang, “This represents one of the most extensive genomic collections of wild potatoes ever subjected to analysis.” The team identified two genes as vital for tuber formation: SP6A, present in tomatoes, and IT1, found in Etuberosum. Individually, neither gene is sufficient. However, when these two genes converge, as they do in the potato plant, they interact synergistically, initiating the potent process that converts subterranean stems into starchy, palatable tubers.
James Mallet, a professor of organismic and evolutionary biology at Harvard University, hailed the study as “groundbreaking.” He elaborated, “It demonstrates how a hybridization event can catalyze the development of a novel organ—and even give rise to a new lineage encompassing numerous species.” Potatoes acquired a robust genetic blend from both parental lines, resulting in a hardy, resilient plant. Their tubers serve as energy reservoirs, aiding the plant’s survival through winter or drought conditions and enabling reproduction without reliance on seeds or pollinators. Rather, new plants emerge from buds that develop on the tubers.
These nutrient-dense organs facilitated the potato’s flourishing in the nascent, high-altitude environments of the burgeoning Andes. The plants adapted and disseminated, resulting in a dramatic expansion of diversity. Human intervention led to the domestication of several wild species, specifically those chosen for their large, edible tubers. Dr. Sandra Knapp, a botanist at the Natural History Museum in London, stated, “The Indigenous communities in the Andes cultivate hundreds of potato varieties.” She continued, “In contrast, Europe boasts perhaps five, all derived from a single species: Solanum tuberosum.”
During the 16th century, potatoes were transported from the Andes to other parts of the world aboard Spanish vessels. Though initially regarded with suspicion—due to its subterranean growth, absence in biblical texts, and unusual appearance—it was rapidly accepted for its nutritional value and resilience in adverse conditions. Consequently, it evolved into a fundamental dietary element throughout Europe and globally. The future trajectory of this adaptable plant remains uncertain, given that its closest relatives have diverged too significantly for natural hybridization to reoccur.
However, researchers are actively investigating artificial methods to generate novel varieties. Professor Huang stated, “We are currently engaged in a project aimed at enabling potatoes to reproduce via seeds.” He also mentioned, “Furthermore, we are introducing the IT1 gene and other essential potato genes into tomatoes, with the goal of enabling them to develop tubers.” At present, these endeavors remain purely experimental. Nonetheless, if successful, the tomato’s role could extend beyond merely being part of the potato’s evolutionary history to becoming a component of its future as well.
