Divergent pollination system and morph-dependent effects of corolla length on inaccuracy of reciprocity and reproductive success of a distylous species of Rubiaceae

Premise of this study: Salvia is the most species-rich genus in Lamiaceae, encompassing approximately 1000 species distributed all over the world. We sought a new evolutionary perspective for Salvia by employing macroevolutionary analyses to address the tempo and mode of diversification. To study the association of floral traits with speciation and extinction, we modeled and explored the evolution of corolla length and the lever-mechanism pollination system across our Salvia phylogeny. Methods: We reconstructed a multigene phylogeny for 366 species of Salvia in the broad sense including all major recognized lineages and numerous species from Iran, a region previously overlooked in studies of the genus. Our phylogenetic data in combination with divergence time estimates were used to examine the evolution of corolla length, woody vs. herbaceous habit, and presence vs. absence of a lever mechanism. We investigated the timing and dependence of Salvia diversification related to corolla length evolution through a disparity test and BAMM analysis. A HiSSE model was used to evaluate the dependency of diversification on the lever-mechanism pollination system in Salvia. Key Results: Based on recent investigations and classifications, Salvia is monophyletic and comprises ~1000 species. Our inclusion, for the first time, of a comprehensive sampling for Iranian species of Salvia provides higher phylogenetic resolution for southwestern Asian species than obtained in previous studies. A medium corolla length (15-18mm) was reconstructed as the ancestral state for Salvia with multiple shifts to shorter and longer corollas. Macroevolutionary model analyses indicate that corolla length disparity is high throughout Salvia evolution, significantly different from expectations under a Brownian motion model during the last 28 million years of evolution. Our analyses show evidence of a higher diversification rate of corolla length for some Andean species of Salvia compared to other members of the genus. Based on our tests of diversification models, we reject the hypothesis of a direct effect of the lever mechanism on Salvia diversification. Conclusions: Using a broader species sampling than previous studies, we obtained a well-resolved phylogeny for southwest Asian species of Salvia. Corolla length is an adaptive trait throughout the Salvia phylogeny with a higher rate of diversification in the South American clade. Our results suggest caution in considering the lever-mechanism pollination system as one of the main drivers of speciation in Salvia.

Download Full-text

Disentangling the pollination system of the food-deceptive orchid Anacamptis longicornu (Orchidaceae): from breeding system to spatio-temporal variation in reproductive success

Plant Biosystems - An International Journal Dealing with all Aspects of Plant Biology ◽

10.1080/11263504.2019.1610110 ◽

2019 ◽

Vol 154 (3) ◽

pp. 306-315 ◽

Cited By ~ 2

Author(s):

Miquel Capó ◽

Joana Cursach ◽

Juan Rita

Keyword(s):

Reproductive Success ◽

Temporal Variation ◽

Breeding System ◽

Pollination System ◽

Spatio Temporal

Download Full-text

Generalised pollination of Diuris alba (Orchidaceae) by small bees and wasps

Australian Journal of Botany ◽

10.1071/bt06207 ◽

2007 ◽

Vol 55 (6) ◽

pp. 628 ◽

Cited By ~ 13

Author(s):

James O. Indsto ◽

Peter H. Weston ◽

Mark A. Clements ◽

Adrian G. Dyer ◽

Michael Batley ◽

...

Keyword(s):

Reproductive Success ◽

New South ◽

New South Wales ◽

Structural Similarity ◽

Pollination System ◽

Flower Visitors ◽

Ancestral Condition ◽

Floral Rewards ◽

South Wales

Most Diuris species possess flowers of pea-like form and colour, and occur in association with flowering peas of the tribe Mirbeliae. Previous studies of the pollination of Diuris maculata sensu lato have found evidence for guild mimicry of pea flowers. The flowers of Diuris alba are also pea-like in form but not in colour, and this species is frequently found in habitats where peas are uncommon or absent. We investigated the pollination of Diuris alba, which we expected may have a distinct pollination system at Lake Munmorah, New South Wales. Many Diuris species lack floral rewards, but D. alba produced a small amount of nectar. Flower visitors, and hence putative pollinators, were mainly female Exoneura bees, but also the wasps Eurys pulcher and a Paralastor species. Reproductive success of D. alba, both in woodland containing abundant Dillwynia retorta and in heathland where this pea was absent, was higher than in the previously studied D. maculata s.l. We suggest that the pollination of D. alba is more generalised than that found in the legume guild mimic D. maculata s.l. Although its flowers may display structural similarity to pea flowers, other characteristics suggest that its pollination system has diverged from a presumed pea-mimicry ancestral condition.

Download Full-text

Flowering dynamics and pollination system of the sedgeRhynchospora ciliata(Vahl) Kükenth (Cyperaceae): does ambophily enhance its reproductive success?

Plant Biology ◽

10.1111/j.1438-8677.2012.00574.x ◽

2012 ◽

Vol 14 (6) ◽

pp. 881-887 ◽

Cited By ~ 11

Author(s):

A. C. G. Costa ◽

I. C. Machado

Keyword(s):

Reproductive Success ◽

Pollination System

Download Full-text

The generalist pollination system and reproductive success of Calluna vulgaris in the Upper Ardenne

Canadian Journal of Botany ◽

10.1139/b98-133 ◽

1998 ◽

Vol 76 (11) ◽

pp. 1843-1851 ◽

Cited By ~ 14

Author(s):

Grégory Mahy ◽

Jacques De Sloover ◽

Anne-Laure Jacquemart

Keyword(s):

Reproductive Success ◽

Calluna Vulgaris ◽

Sampling Location ◽

Wind Pollination ◽

Seed Number ◽

Pollinator Visitation ◽

Pollination System ◽

Exclusion Experiments ◽

Syrphid Flies ◽

Pollination Systems

Although specialist pollination systems are often thought to be the outcome of selection, wide evidence exists for generalization within plant-pollinator interactions. We studied the pollination system and reproductive success of Calluna vulgaris (L.) Hull over 3 years in an Upper Ardennes site in Belgium. A wide variety of insect visitors was recorded including Hymenoptera, Diptera, and Lepidoptera. Relative abundance of families and species of visitors varied markedly among years except for bees. Bumblebees and honeybees were the most efficient pollinators at the study site. Syrphid flies, mainly large ones, acted as important co-pollinators because of their high relative frequency. Calluna pollen was also dispersed by wind, and insect-exclusion experiments demonstrated that wind pollination contributed to reproductive success. Following open pollination, fruit set was high, ranging from 82.0 to 97.2% and independent of sampling location. Mean seed number per fruit was less than maximum potential seed number and varied strongly among sampling locations. We discuss this pollination system (generalist insect and wind) in terms of the ecological and geographical success of the species.Key words: Calluna vulgaris, pollinator visitation, insects, wind pollination, reproductive success.

Download Full-text