The emergence of the contemporary potato (Solanum tuberosum) is attributed to an ancestral crossbreeding event between tomato plants and potato-like flora indigenous to South America, occurring approximately 8 to 9 million years prior. This pivotal evolutionary occurrence, as elucidated by an international consortium of biologists from China, Canada, Germany, the United States, and the United Kingdom, instigated the development of the tuber, a specialized subterranean organ for nutrient storage characteristic of plants such as potatoes, yams, and taros.
Interspecific hybridization holds the potential to instigate species diversification by fostering novel allele combinations and traits. The cultivated potato, alongside its 107 wild relatives within the Petota lineage, universally exhibits the defining characteristic of subterranean tubers; however, the precise molecular underpinnings of tuberization and its correlation with extensive species diversification have remained an enigma. Through comprehensive genomic analyses encompassing 128 genomes, including 88 resolved haplotype genomes, researchers have ascertained that the Petota lineage boasts an ancient hybrid genesis. All constituents display a consistent, intermingled genomic heritage, originating from the Etuberosum and Tomato lineages approximately 8 to 9 million years ago. Image credit: Zhang et al., doi: 10.1016/j.cell.2025.06.034.
Currently, the globally cultivated potato ranks as the third most significant staple foodstuff, contributing substantially, alongside wheat, rice, and maize, to approximately 80% of humanity’s caloric intake.
Visually, contemporary potato plants bear a striking resemblance to three tuber-less species from Chile known as Etuberosum.
Phylogenetic investigations indicate a closer evolutionary kinship between potato plants and tomatoes.
To resolve this apparent discrepancy, Dr. Sanwen Huang of the Agricultural Genomics Institute at Shenzhen, affiliated with the Chinese Academy of Agricultural Sciences and the Chinese Academy of Tropical Agricultural Sciences, along with his research team, undertook an extensive analysis of 450 genomes derived from cultivated potatoes and 56 wild potato species.
“Our discoveries illuminate how interspecies hybridization can precipitate the evolution of novel characteristics, thereby enabling the proliferation of additional species,” commented Dr. Huang.
“We have finally elucidated the mystery surrounding the origin of potatoes.”
“The procurement of wild potato samples presents considerable challenges, rendering this dataset the most exhaustive compilation of wild potato genomic data ever subjected to analysis,” stated Dr. Zhiyang Zhang, a researcher at the Agricultural Genomics Institute at Shenzhen, part of the Chinese Academy of Agricultural Sciences.
The authors’ findings reveal that the genetic makeup of every potato species comprises a stable, balanced admixture of genetic material originating from both Etuberosum and tomato progenitors, strongly suggesting that potatoes are the product of an ancient hybridization event between these two groups.
Although Etuberosum and tomatoes are classified as distinct species, they shared a common ancestral lineage approximately 14 million years ago.
Despite a divergence period of roughly 5 million years, they retained the capacity for interbreeding, leading to the genesis of the earliest potato plants exhibiting tubers around 8 to 9 million years ago.
The research team also pinpointed the evolutionary trajectory of the potato’s crucial tuber-forming genes, identifying them as a composite of genetic contributions from both parent species.
It was discovered that the SP6A gene, functioning as a master regulatory element that signals the plant to initiate tuber development, was inherited from the tomato lineage.
Another critical gene, designated IT1, which plays a role in regulating the growth of the subterranean stems that develop into tubers, originated from the Etuberosum lineage.
The absence of either of these genetic components would render the hybrid offspring incapable of tuber production.
This significant evolutionary advancement coincided with a period of rapid geological uplift in the Andes Mountains, a phase marked by the emergence of novel ecological environments.
The possession of tubers for underground nutrient storage enabled early potatoes to adapt swiftly to the evolving environmental conditions, facilitating their survival in the challenging mountainous terrain.
Furthermore, tubers provide potato plants with an alternative mode of reproduction, independent of seeds or pollination. They propagate new plants through the sprouting of buds directly from the tuber.
This reproductive strategy fostered their rapid expansion and colonization of diverse ecological niches, ranging from temperate grasslands to elevated, frigid alpine meadows across Central and South America.
“The acquisition of a tuber provided potatoes with a substantial evolutionary advantage in adverse environments, fueling a remarkable proliferation of new species and contributing to the rich biodiversity of potatoes that we utilize and depend upon today,” Dr. Huang remarked.
The investigation was published on July 31, 2025, in the esteemed journal Cell.
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Zhiyang Zhang et al. Ancient hybridization underlies tuberization and radiation of the potato lineage. Cell, published online July 31, 2025; doi: 10.1016/j.cell.2025.06.034
