Avocados are everywhere — in supermarkets, on toast, in guacamole — but almost every one you have ever eaten came from the same plant. Now, scientists have discovered a hidden treasure trove of avocado diversity in Nicaragua's rainforests that could reshape the future of one of the world's most popular fruits.
A team led by Kevin Wann, a doctoral researcher at Texas A&M University, ventured into Central America's lowland rainforests and identified 32 genetically distinct avocado varieties — known as landraces — that have been cultivated and tended by local farmers for thousands of years. The findings, published in the journal Plants People Planet, reveal that the genetic breadth of the avocado is far wider than science had previously documented.
A World Built on One Avocado
The problem the discovery addresses is as simple as it is precarious: nearly every commercially grown avocado in the world is a Hass avocado, produced through clonal grafting. Every Hass tree is genetically identical to every other Hass tree. That means the entire global supply — around 11 million metric tons per year — is vulnerable to the exact same diseases, temperature shifts, and climate disruptions.
It is the same vulnerability that devastated the banana industry in the mid-20th century, when the Gros Michel variety was nearly wiped out by Panama disease. Today, the commercial avocado faces similar threats, particularly Phytophthora root rot, a fungal disease that destroys avocado trees' root systems.
Here is where the Nicaraguan landraces could prove transformative: local farmers confirmed that many of these lowland varieties have never suffered from root rot. They have been growing in the humid lowlands for generations, developing natural resistance that commercial Hass avocados simply do not have.
A Journey Through Ancient Genetics
The story of how these varieties came to Nicaragua is itself remarkable. Avocados originated in South America and were first transported north to Central America around 5,000 years ago by early human civilizations. As the fruit spread, it hybridized with local wild relatives, creating an extraordinary diversity of avocado forms adapted to different environments.
Wann analyzed DNA from 47 native avocado landraces, 32 of which came from Nicaragua. When compared against genetic data from more than 200 other avocado lineages, the Nicaraguan varieties turned out to be genetically tied to avocados found further south in Colombia — not to the commercial varieties grown in Mexico. This revealed that many local landraces are descended from South American populations that migrated north long before modern agriculture began.
"We could potentially tap into this genetic diversity to conserve commercial avocado plants that are vulnerable to disease," said Wann. "There is a much wider breadth of avocado diversity that science had not yet documented."
What Comes Next
The research is still in its early stages, but the implications are significant. Plant breeders could use the Nicaraguan landraces to develop new disease-resistant commercial varieties, or to create hybrids that maintain the taste and appearance of Hass while borrowing the hardiness of native varieties.
Beyond disease resistance, the discovery also represents a record of traditional agricultural knowledge. The farmers of Nicaragua's lowlands have been selectively cultivating these avocados for generations, preserving genetic diversity that has proven invaluable in an era of climate change and global food insecurity.
For now, the avocado you eat tomorrow will likely still be a Hass. But scientists are working to ensure that the global food system has options — and that a tiny village in Nicaragua may have quietly been keeping those options alive for thousands of years.
