Available data show that in mutualistic nursery pollination systems, several host species may share pollinators by producing similar odors at flower receptivity. Ficus species seem to be capable of retaining their identity while sharing pollinators. The species complex of Ficus auriculata provides an extreme example of how potentially hybridizing sympatric Ficus species seem to retain their genetic and biological identity.

     Dr. WEI Zuodong of Xishuangbanna Tropical Botanical Garden (XTBG) and his teacher Finn Kjellberg from France investigated pollinator specificity and genetic structuring within and among the morphological Ficus groups that they detected during field studies.

     They documented that although Ficus auriculata co-occurred over large distances with very closely related other forms of its species group, it maintained its genetic homogeneity over the investigated 750 km of co-occurrence. Genetic homogeneity was maintained in F. auriculata despite 1) sharing pollinators with southern F. oligodon and F. hainanensis, 2)production of viable offspring in crosses between F. auriculata, and both southern F. oligodon and F. hainanensis and 3) fertility of F1 hybrids between F. auriculata and southern F. oligodon.

The researchers proposed that ecological differentiation among forms, coupled with limited overlap of reproductive season had facilitated the maintenance of those inter-fertile forms. As such, establishment of pollinator host specificity might not be a prerequisite for sympatric diversification in Ficus.

The study entitled “Genetic structure and hybridization in the species group ofFicus auriculata: can closely related sympatricFicus species retain their genetic identity while sharing pollinators?” has been published online in Molecular Ecology.