The World's Potato Diversity Fits Inside One Building in Lima

Every commercially significant potato variety grown anywhere in the world today — Russet Burbank in Idaho, Rooster in Ireland, Qingshu 9 in northwest China — ultimately traces its genetic lineage back to a relatively small set of Andean ancestors. Most of what remains of that original diversity, the wild relatives and thousands of years of farmer-bred landrace varieties that never made it into commercial agriculture, is conserved in one place: the International Potato Center's genebank in Lima, Peru.

The active cultivated potato collection today totals 5,205 accessions, including 4,797 traditional landrace cultivars sourced from 18 countries — overwhelmingly the Andean region — plus improved breeding-program material. That number is smaller than it used to be, and deliberately so: the collection once peaked at 17,347 accessions before a systematic duplicate-removal effort curated it down to today's total. Fewer entries, but each one genetically distinct — a quality-control decision, not a loss of diversity.

The taxonomic range inside that collection is genuinely wide: nine potato species spanning ploidy levels from diploid through pentaploid (a range of chromosome-set counts most cultivated crops don't approach). Solanum tuberosum subsp. andigenum — the Andean cultivated subspecies — is the single largest group, at 3,388 accessions on its own.

The genebank isn't a one-way vault that only takes deposits from history. Through the Parque de la Papa ("Potato Park") initiative — a community-based conservation project in the Peruvian Andes — indigenous farming communities actively maintain traditional varieties in situ, in real fields under real growing conditions, rather than only in a laboratory. Over 200 additional cultivated potato varieties containing unique genetic material have flowed from that living conservation work into CIP's formal genebank record, a two-way relationship between active farming communities and institutional science that a lot of genebanks elsewhere don't have.

Potato doesn't breed true from true seed the way many staple crops do, which makes conservation genuinely harder than just storing seed packets in a cool room. CIP runs four separate, redundant systems to protect against catastrophic loss. The entire clonal collection has been maintained through in vitro tissue culture — live plant tissue grown in a sterile lab environment — for more than 30 years, requiring periodic regeneration to stay viable. Roughly 450 new accessions are added annually to long-term cryopreservation, storing plant tissue in liquid nitrogen at -196°C, a far more durable, lower-maintenance method than active tissue culture once material is safely frozen.

Beyond Lima itself, most of the collection is backed up a second time at CIP's research station in Huancayo, in the Peruvian Andes — a geographically separate site within Peru. And farmer-produced true botanical seed from traditional cultivars has been deposited in the Svalbard Global Seed Vault in Norway, the globally recognized backup-of-last-resort that protects crop diversity from genebanks worldwide against the kind of single-site disaster — fire, funding collapse, political upheaval — that has permanently destroyed other collections throughout agricultural history.

It's worth being clear about why any of this matters beyond historical preservation for its own sake: this exact collection is the working raw material behind modern potato breeding worldwide. Disease-resistance and climate-adaptation traits bred into commercial varieties documented elsewhere on this site — China's Qingshu 9 (bred from CIP's UNICA line), breeding programs across South Asia, national programs throughout Africa — trace directly back to wild and landrace genetics held in this Lima collection. When a breeder anywhere in the world needs a specific resistance trait that modern commercial varieties lack, there's a real chance the genetic answer is sitting in a test tube or a liquid-nitrogen tank in Peru, put there specifically so that question could someday be asked.