Brown rot is a serious fungal disease affecting fruit trees like apricots, cherries, and plums. Researchers collected over 400 fungal isolates from Iranian fruit orchards and identified two main species causing the disease, with one species being far more common. By developing new genetic tests, scientists discovered both male and female forms of the fungi exist in equal proportions, suggesting the disease could evolve through sexual reproduction, which has important implications for managing the disease in orchards.