An avocado flower does something that sounds like a scheduling error. It opens as one sex, closes, and later opens as the other. The tree has been doing this for as long as anyone has been trying to make sense of its pollination.
Researchers at UC Davis and UC Riverside have now found a genetic explanation for that daily handoff. The work addresses one of the crop's oldest pollination puzzles and gives breeders a possible way to identify flower types before a tree reaches maturity, according to the UC Davis study report.
A Flower With a Split Shift
Avocado flowers are not permanently male or female in the ordinary sense. Their reproductive function changes during the day, a trait that helps explain why avocado orchards rely on compatible flowering patterns for pollination. The newly described switch helps connect that visible behavior to the tree's underlying genetics.
Jeffrey Groh, a former UC Davis Ph.D. student who is now a postdoctoral fellow at UC Berkeley, examined avocado plants in greenhouse research. The study's value is less about changing what a grower sees in an orchard tomorrow than about giving breeders a clearer map of what is happening inside the flower.
That map matters because avocado breeding is slow. A breeder normally has to wait for trees to grow and flower before learning useful information about their reproductive behavior. A genetic marker tied to flower type could move some of that sorting earlier in the process, potentially shaving years from the path to a new variety, as UC Riverside describes.
Breeding Before the Blossoms
For California's avocado industry, the practical promise is selection. Breeders could use the discovery to organize crosses and evaluate young trees before waiting through another growth cycle, then test the most useful candidates for yield, orchard performance, and resilience.
The research does not produce a new commercial variety by itself, and it does not remove the need for field trials. It supplies a biological clue. The hard, familiar work—raising trees, matching flowering types, measuring fruit set, and finding out what survives a real season—still follows.
That last part is becoming less theoretical. UC Agriculture and Natural Resources recently addressed heat damage in avocado trees, advising growers to assess trees after excessive temperatures and, in lightly damaged cases, leave them alone rather than rushing into corrective work. The heat guidance from UCANR puts the breeding discovery against the conditions new varieties will eventually have to face.
From Greenhouse Switch to Orchard Test
The next useful question for California growers is not whether an avocado tree can change sex; it can. It is whether researchers can turn the genetic finding into a reliable screening tool and then connect that tool to traits an orchard can pay for: consistent fruit set, useful yield, and performance through heat.
That work will take place on a breeder's timetable rather than a headline's. The discovery gives California programs a way to make earlier choices, but the commercial proof will come only when selected trees leave the greenhouse and accumulate seasons in the field.