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Evidence for the long‐term maintenance of a rare self‐incompatibility system in Oleaceae
Author(s) -
Vernet Philippe,
Lepercq Pierre,
Billiard Sylvain,
Bourceaux Angélique,
Lepart Jacques,
Dommée Bertrand,
SaumitouLaprade Pierre
Publication year - 2016
Publication title -
new phytologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.742
H-Index - 244
eISSN - 1469-8137
pISSN - 0028-646X
DOI - 10.1111/nph.13872
Subject(s) - oleaceae , biology , evolutionary biology , dioecy , zoology , botany , pollen
Summary A rare homomorphic diallelic self‐incompatibility ( DSI ) system discovered in Phillyrea angustifolia (family Oleaceae, subtribe Oleinae) can promote the transition from hermaphroditism to androdioecy. If widespread and stable in Oleaceae, DSI may explain the exceptionally high rate of androdioecious species reported in this plant family. Here, we set out to determine whether DSI occurs in another Oleaceae lineage. We tested for DSI in subtribe Fraxininae, a lineage that diverged from subtribe Oleinae c . 40 million yr ago. We explored the compatibility relationships in Fraxinus ornus using 81 hermaphrodites and 25 males from one natural stand and two naturalized populations using intra‐ and interspecific stigma tests performed on F. ornus and P. angustifolia testers. We uncovered a DSI system with hermaphrodites belonging to one of two self‐incompatibility ( SI ) groups and males compatible with both groups, making for a truly androdioecious reproductive system. The two human‐founded populations contained only one of the two SI groups. Our results provide evidence for the evolutionary persistence of DSI . We discuss how its stability over time may have affected transitions to other sexual systems, such as dioecy.