Scientists solve the 100-year-old mystery behind why avocado flowers change sex over two days

For more than a century, avocado growers have known that not all avocado trees flower in the same way. Some trees produce flowers that function as females in the morning before becoming males the following afternoon, while others follow the opposite schedule. This unusual rhythm has long shaped how orchards are planted, with growers pairing different flowering types to maximise pollination and fruit production. Although the pattern has been carefully documented for generations, the genetic mechanism behind it remained unknown. Now, researchers from the University of California, Davis and the University of California, Riverside have identified a single gene that controls this remarkable flowering cycle, solving one of the oldest mysteries in avocado biology and offering breeders a powerful new tool for developing improved varieties.Every avocado flower opens twice, first as a female and then as a maleThe findings come from the Proceedings of the National Academy of Sciences (PNAS) study ‘Balanced Polymorphism in a Floral Transcription Factor Underlies the Ancient Rhythm of Daily Sex Alternation in Avocado’ by J.S. Groh and colleagues.Unlike most flowering plants, each avocado flower...