Abstract

The tropics are known for their high diversity of plants, animals, and biotic interactions, but the role of the speciose endophytic fungi in these interactions has been mostly neglected. We report a unique interaction among plant sex, bees, and endophytes on the dioecious shrub, Baccharis dracunculifolia (Asteraceae). We assessed whether there was an association between resin collection by bees and fungal endophytes considering the host plant sex. We hypothesized that resin collection by the Africanized honey bee, Apis mellifera L. (Apidae) could favor the entry of endophytes in B. dracunculifolia. Specifically, we tested the hypotheses that (1) bees damage the leaf buds of female and male plant at different proportions; (2) damage on leaf buds increases the richness of endophytic fungi; (3) endophyte richness differs between female and male plants; and (4) in vitro growth of endophytes depends on the sex of the plant individual from which the resin was extracted. Endophyte richness and proportion of leaf bud damage did not vary between the plant sexes. However, species similarity of endophytes between female and male plants was 0.33. Undamaged leaf buds did not show culturable endophytes, with all fungi exclusively found in damaged leaf buds. Endophyte composition changed with the plant sex. The endophytes exclusively found in female plants did not develop in the presence of male resin extract. These findings highlight that resin collection by A. mellifera for propolis production favors the entry of endophytic fungi in B. dracunculifolia. Additionally, endophyte composition and growth are influenced by plant sex.