Go to any bar and order a “Cuba Libre.” Dee if the bartender adds a lime garnish without provocation. They won’t, because due to “greening,” there’s a lime shortage, resulting in limes now costing approximately $34,598,756.00 per case.

To combat the rising costs of limes, University of Florida scientists analyzed the genome sequences of 10 diverse citrus varieties for the first time. They hope their findings will unlock clues as to how to genetically avoid greening, a bacterial infection devastating crops in North America.

Though we now have lots of citrus fruits, the team found that the ancestors of oranges, limes, and other citrus fruits, date back more than 5 million years, all the way to two wild citrus species from Southeast Asia.  The citrus fruits have a “very narrow genetic diversity,” weakening the citrus gene pool the same way it would the animal gene pool. In addition, because new citrus trees are usually produced by grafting (a method of propagation binding the fruit bearing part of one tree to the root system of another), if one tree is susceptible to greening, all of them are.

“Citrus has incestuous genes – nothing is pure,” said Fred Gmitter, a UF Institute of Food and Agricultural Sciences faculty member, based at UF’s Citrus Research and Education Center in Lake Alfred. “Now that we understand the genetic structure of sweet orange, for example, we can imagine reproducing early citrus domestication using modern breeding techniques that could draw from a broader pool of natural variation and resistance.”

They’d better move fast as the current greening blight is said to be so bad  it could wipe out the U.S. citrus industry within a decade if left unchecked. Previous treatment attempts have included trying to control the Asian citrus psyllid, a tiny bug that carries the greening bacteria. For now, the best anti-greening method available involves quickly removing infected trees and providing additional nutrition to healthy trees to combat the infection.

Bad news, given that it’s mojito season.