Extended Data Fig. 1: Characteristics of fruit and seed of Citrus-related genera (1–7), early-diverging Citrus (8–10) and three groups of Citrus species (11–25).

1, Murraya paniculata; 2, Atalantia buxifolia; 3, Glycosmis pentaphylla; 4, Bergera koenigii; 5, Clausena lansium; 6, Aegle marmelos; 7, Citropsis gilletiana; 8, Citrus trifoliata; 9, Citrus mangshanensis; 10, Citrus ichangensis; 11, Citrus linwuensis; 12, Citrus reticulata; 13, Citrus aurantium; 14, Citrus sinensis; 15, Citrus hystrix; 16, Citrus hongheensis; 17, Citrus maxima; 18, Citrus medica; 19, Citrus indica; 20, Citrus paradisi; 21, Citrus limon; 22, Citrus polyandra; 23, Citrus australasica; 24, Citrus hindsii; 25, Citrus glauca. Individual pieces of fruit from different pictures were collected and are shown together. Scale bars, 1 cm. Generally, a large number of seeds and the emergence of juice vesicles in the fruits of the early-diverging Citrus species were observed, showing an intermediate form between Citrus-related genera and Citrus species. Scale bars = 1 cm.