Phylogenetic relationships of functionally dioecious Ficus (Moraceae) based on ribosomal DNA sequences and morphology

Figs (Ficus, Moraceae) are either monoecious or gynodioecious depending on the arrangement of unisexual florets within the specialized inflorescence o r syconium. The gynodioecious species are functionally dioecious due to the impact of pollinating fig wasps (Hymenoptera: Agaonidae) on the maturation of fig seeds. The evolutionary relationships of functionally dioecious fig s (Ficus subg. Ficus) were examined through phylogenetic analyses based on the internal transcribed spacer (ITS) region of nuclear ribosomal DNA and m orphology. Forty-six species representing each monoecious subgenus and each section of functionally dioecious subg. Ficus were included in parsimony a nalyses based on 180 molecular characters and 61 morphological characters t hat were potentially informative. Separate and combined analyses of molecul ar and morphological data sets suggested that functionally dioecious figs a re not monophyletic and that monoecious subg. Sycomorus is derived within a dioecious clade. The combined analysis indicated one or two origins of fun ctional dioecy in the genus and at least two reversals to monoecy within a functionally dioecious lineage. The exclusion of breeding system and relate d characters from the analysis also indicated two shifts from monoecy to fu nctional dioecy and two reversals. The associations of pollinating fig wasp s were congruent with host fig phylogeny and further supported a revised cl assification of Ficus.