TY  - JOUR
A1  - Breitkopf, Hendrik
A1  - Onstein, Renske E.
A1  - Cafasso, Donata
A1  - Schlüter, Philipp M.
A1  - Cozzolino, Salvatore
T1  - Multiple shifts to different pollinators fuelled rapid diversification in sexually deceptive Ophrys orchids
JF  - New phytologist : international journal of plant science
N2  - Episodes of rapid speciation provide unique insights into evolutionary processes underlying species radiations and patterns of biodiversity. Here we investigated the radiation of sexually deceptive bee orchids (Ophrys). Based on a time-calibrated phylogeny and by means of ancestral character reconstruction and divergence time estimation, we estimated the tempo and mode of this radiation within a state-dependent evolutionary framework. It appears that, in the Pleistocene, the evolution of Ophrys was marked by episodes of rapid diversification coinciding with shifts to different pollinator types: from wasps to Eucera bees to Andrena and other bees. An abrupt increase in net diversification rate was detected in three clades. Among these, two phylogenetically distant lineages switched from Eucera to Andrena and other bees in a parallel fashion and at about the same time in their evolutionary history. Lack of early radiation associated with the evolution of the key innovation of sexual deception suggests that Ophrys diversification was mainly driven by subsequent ecological opportunities provided by the exploitation of novel pollinator groups, encompassing many bee species slightly differing in their sex pheromone communication systems, and by spatiotemporal fluctuations in the pollinator mosaic.
KW  - Andrena
KW  - diversification rates
KW  - Eucera
KW  - Ophrys
KW  - pollination syndrome
KW  - pollinator shift
KW  - sexual deception (SD)
KW  - species radiation
Y1  - 2015
U6  - https://doi.org/10.1111/nph.13219
SN  - 0028-646X
SN  - 1469-8137
VL  - 207
IS  - 2
SP  - 377
EP  - 389
PB  - Wiley-Blackwell
CY  - Hoboken
ER  - 
TY  - JOUR
A1  - Lumaga, Maria Rosaria Barone
A1  - Cozzolino, Salvatore
A1  - Kocyan, Alexander
A1  - Menale, Bruno
A1  - Rudall, Paula J.
T1  - Exine micromorphology and ultrastructure in Neottieae (Epidendroideae, Orchidaceae)
JF  - Plant systematics and evolution
N2  - The diverse epidendroid orchid tribe Neottieae is characterized by multiple transitions between autotrophy and mycoheterotrophy, allogamous and autogamous mating systems, pollen released as tetrads or monads, and pollen exine tectate or semitectate. We use transmission and scanning electron microscopy on pollen of ten species of Neottieae to investigate whether the differences in pollen aggregation and exine micromorphology and ultrastructure reflect phylogenetic relationships, or whether this variation is subject to ecological constraints. Our results showed that differences in exine micromorphology are mostly concordant with phylogenetic relationships in Neottieae, i.e. an ascending tendency of pollen ornamentation from tectate (Cephalanthera) to semitectate (e.g. Neottia). In contrast, pollen aggregation, when plotted on the most recent phylogeny, shows repeated transitions between monads and tetrads that could be related to ecological constraints. Tetrads are present in species that are nectar rewarding, whereas monads are common in deceptive species. Cephalanthera is characterized by recalcitrant pollen, including the frequent occurrence of collapsed pollen. In this genus, the observed shifts from allogamous to autogamous or cleistogamous mating systems could help to reduce pollen damage caused by exposure to dry habitats.
KW  - Mating system
KW  - Monads
KW  - Neottieae
KW  - Pollenkitt
KW  - Tetrads
KW  - Ulcerate pollen
Y1  - 2014
U6  - https://doi.org/10.1007/s00606-013-0899-2
SN  - 0378-2697
SN  - 1615-6110
VL  - 300
IS  - 3
SP  - 505
EP  - 515
PB  - Springer
CY  - Wien
ER  -