Development and characterization of microsatellite markers for diploid populations of the wind-pollinated herb Mercurialis annua.

Mercurialis annua is a wind-pollinated annual plant that has long been used as a model for the study of ploidy and sexual-systems evolution. However, no molecular markers are yet available for genetic studies of its diploid populations. Here, we develop and characterize a set of eight polymorphic microsatellite markers for diploid dioecious M. annua. Following an SSR-enrichment protocol, 13 microsatellite markers were proposed, eight of which yielded successful amplification and polymorphism. We screened the eight microsatellite loci in 100 individuals. The number of alleles per marker ranged from 6 to 12, and observed heterozygosity ranged from 0.57 to 0.76. To estimate potential allele scoring errors, these individuals' offspring were genotyped for the same loci, and error rates were estimated from parentage analyses. Error rates ranged from 0 to 6.8%. Cross-amplification tests were performed for congeneric M. huetti and M. canariensis, with successful amplification for seven and six of the eight loci, respectively. The novel microsatellite markers proposed here will be crucial for a multitude of genetic studies of M. annua and further establish its importance as a model species for addressing ecological and population genetic questions

Functional traits explain the Hutchinsonian niches of plant species

CITATION: Martina, T. et al. 2019. Functional traits explain the Hutchinsonian niches of plant species. Global Ecology and Biogeography, 29(3):534–54. doi:10.1111/geb.13048The original publication is available at https://onlinelibrary.wiley.com/journal/14668238Aim: The Hutchinsonian niche is a foundational concept in ecology and evolutionary biology that describes fundamental characteristics of any species: the global maximum population growth rate (rmax); the niche optimum (the environment for which rmax is reached); and the niche width (the environmental range for which intrinsic population growth rates are positive). We examine whether these characteristics are related to inter- and intraspecific variation in functional traits. Location: Cape Floristic Region, South Africa. Time period: Present day. Major taxa studied: Twenty-six plant species (Proteaceae). Methods: We measured leaf, plant-architectural and seed traits across species geographical ranges. We then examined how species-mean traits are related to demographically derived niche characteristics of rmax, in addition to niche optima and widths in five environmental dimensions, and how intraspecific trait variation is related to niche widths. Results: Interspecific trait variation generally exceeded range-wide intraspecific trait variation. Species-mean trait values were associated with variation in rmax (R2 = 0.27) but were more strongly related to niche optima (mean R2 = 0.56). These relationships generally matched trait–environment associations described in the literature. Both species-mean traits and intraspecific trait variability were strongly related to niche widths (R2 = 0.66 and 0.59, respectively). Moreover, niche widths increased with intraspecific trait variability. Overall, the different niche characteristics were associated with few, largely non-overlapping sets of traits. Main conclusions: Our study relating functional traits to Hutchinsonian niches demonstrates that key demographic properties of species relate to few traits with relatively strong effects. Our results further support the hypothesis that intraspecific trait variation increases species niche widths. Given that niche characteristics were related to distinct sets of traits, different aspects of environmental change might affect axes of trait variation independently. Trait-based studies of Hutchinsonian niches thus yield important insights into the mechanisms shaping functional biodiversity, which should reinforce the role of traits in functional biogeography.https://onlinelibrary.wiley.com/doi/10.1111/geb.13048Publishers versio

Evolution of pollen and pistil morphologies in Mercurialis annua after experimental evolution at low- and high-density

The dataset corresponds to an evaluation of the evolutionary consequences in terms of the morphology of pollen and pistils, growth dynamics of pollen and pollen production after the evolution at low- versus high-density of plants from the wind-pollinated dioecious plant Mercurialis annua. Our previous work had shown that increased plant density elevates the degree of polyandry such that this dataset permits to test hypotheses related to the effect of sexual selection on pollen and pistil traits. In brief, the plants analysed correspond to experimental evolution lines of M. annua, which have underwent three generations either at low- or high-density (five populations each). After their independent evolution at the contrasted density, seeds resulting from each of those lines were grown in a common garden in which we have evaluated pistil morphology, pollen morphology, pollen growing dynamics and pollen production. Pollen and pistil were harvested on male and female plants and we followed protocols described in the associated publication to evaluate their traits. The dataset is divided in five different sheets : (1) the first sheet ‘read_me’ provides a general description of data described in the other four sheets (see below) and a description of each variable displayed in the four sheets that present the data.(2) the second sheet ‘pistil_morphological_data’ show the data corresponding to the measurements of pistils harvested on females corresponding to our evolutionary lines at low and high density.(3) the third sheet ‘pollen_morphological_data’ provides the data of the measurements of pollen grain and tubes of pollen that was harvested on males of our evolutionary lines.(4) the fourth sheet ‘pollen_germination_data’ provides the counts of pollen that had germinated or not, as well as the pollen density on the slide, after four hours of incubation in the growth medium for male plants from our evolutionary lines.(5) the fifth sheet ‘pollen_weight_data’ provides the data of the weighting of fresh pollen harvested from eight males from the evolutionary lines at low and high density.THIS DATASET IS ARCHIVED AT DANS/EASY, BUT NOT ACCESSIBLE HERE. TO VIEW A LIST OF FILES AND ACCESS THE FILES IN THIS DATASET CLICK ON THE DOI-LINK ABOV

Rapid divergence in vegetative morphology of a wind-pollinated plant between populations at contrasting densities.

Plant sexual dimorphism is thought to evolve in response to sex-specific selection associated with competition for access to mates or resources, both of which may be density dependent. In wind-pollinated plants in particular, vegetative traits such as plant size and architecture may influence resource acquisition and both pollen dispersal and receipt, with potential conflict between these two components of fitness. We evaluated the role of plant density in shaping plant traits by measuring evolutionary responses in experimental populations of the sexually dimorphic wind-pollinated plant Mercurialis annua. After three generations of evolution, we observed divergence between high- and low-density populations in several vegetative traits, whereas there was no divergence for reproductive traits. A reversal in the direction of sexually dimorphic traits expressed in young plants evolved in both low- and high-density populations compared to the original population (stored as seeds). Compared to the source population, males at high density evolved to be taller when young, whereas at low density young females tended to become smaller. These results demonstrate that a simple change in plant density can induce age-dependent and sex-specific evolution in the ontogeny of vegetative organs, and illustrates the power of experimental evolution for investigating plant trait evolution

Sex-specific strategies of resource allocation in response to competition for light in a dioecious plant.

The differential plasticity hypothesis suggests that sexual dimorphism in dioecious plants could evolve in response to sex-specific resource requirements for reproduction (i.e., high carbon requirements for ovules and high nitrogen demands for pollen). When resources become limiting during growth, males and females should, therefore, adjust their allocation to resource-harvesting organs differently. To investigate the potential for plants to respond to resource limitation late in life and to test the differential plasticity hypothesis, we grew male and female individuals of the annual wind-pollinated plant Mercurialis annua in a common garden. Late in the growth season, we simulated a change in competition by decreasing plant density in half of the replicates. We measured both allocation to vegetative and reproductive traits and analyzed the relative allocation to reproduction vs. growth. Males and females differentially adjusted their resource allocation in response to varying plant densities, despite the fact that they were reproductively mature. Males maintained the same relative allocation of resource to reproductive vs. vegetative tissues at both densities. In contrast, females reduced vegetative growth proportionally less than seed production at the higher density. Our results highlight the dynamic nature of allocation decisions taken by plants, which respond quickly and in a sexually dimorphic way to changes in their competitive circumstances. The existence of resource 'currencies' limiting male and female functions differently have potentially led to the evolution of sex-specific strategies of resource acquisition and deployment, with females conserving resources for vegetative organs to ensure their future carbon-rich reproduction

Functional traits explain the Hutchinsonian niches of plant species

Aim: The Hutchinsonian niche is a foundational concept in ecology and evolutionary biology that describes fundamental characteristics of any species: the global maximum population growth rate (rmax); the niche optimum (the environment for which rmax is reached); and the niche width (the environmental range for which intrinsic population growth rates are positive). We examine whether these characteristics are related to inter- and intraspecific variation in functional traits. Location: Cape Floristic Region, South Africa. Time period: Present day. Major taxa studied: Twenty-six plant species (Proteaceae). Methods: We measured leaf, plant-architectural and seed traits across species geographical ranges. We then examined how species-mean traits are related to demographically derived niche characteristics of rmax, in addition to niche optima and widths in five environmental dimensions, and how intraspecific trait variation is related to niche widths. Results: Interspecific trait variation generally exceeded range-wide intraspecific trait variation. Species-mean trait values were associated with variation in rmax (R-2 = 0.27) but were more strongly related to niche optima (mean R-2 = 0.56). These relationships generally matched trait-environment associations described in the literature. Both species-mean traits and intraspecific trait variability were strongly related to niche widths (R-2 = 0.66 and 0.59, respectively). Moreover, niche widths increased with intraspecific trait variability. Overall, the different niche characteristics were associated with few, largely non-overlapping sets of traits. Main conclusions: Our study relating functional traits to Hutchinsonian niches demonstrates that key demographic properties of species relate to few traits with relatively strong effects. Our results further support the hypothesis that intraspecific trait variation increases species niche widths. Given that niche characteristics were related to distinct sets of traits, different aspects of environmental change might affect axes of trait variation independently. Trait-based studies of Hutchinsonian niches thus yield important insights into the mechanisms shaping functional biodiversity, which should reinforce the role of traits in functional biogeography

Life-History Traits Evolved Jointly with Climatic Niche and Disturbance Regime in the Genus Leucadendron (Proteaceae).

Organisms have evolved a diversity of life-history strategies to cope with variation in their environment. Persistence as adults and/or seeds across recruitment events allows species to dampen the effects of environmental fluctuations. The evolution of life cycles with overlapping generations should thus permit the colonization of environments with uncertain recruitment. We tested this hypothesis in Leucadendron (Proteaceae), a genus with high functional diversity native to fire-prone habitats in the South African fynbos. We analyzed the joint evolution of life-history traits (adult survival and seed-bank strategies) and ecological niches (climate and fire regime), using comparative methods and accounting for various sources of uncertainty. In the fynbos, species with canopy seed banks that are unable to survive fire as adults display nonoverlapping generations. In contrast, resprouters with an underground seed bank may be less threatened by extreme climatic events and fire intervals, given their iteroparity and long-lasting seed bank. Life cycles with nonoverlapping generations indeed jointly evolved with niches with less exposure to frost but not with those with less exposure to drought. Canopy seed banks jointly evolved with niches with more predictable fire return, compared to underground seed banks. The evolution of extraordinary functional diversity among fynbos plants thus reflects, at least in part, the diversity of both climates and fire regimes in this region

Serotinia, carácter adaptativo clave en pino carrasco: influencia de factores endógenos y exógenos

La serotinia es un carácter adaptativo clave en plantas frente al fuego, pero puede verse influida por otros factores ambientales y fisiológicos. Determinar sus componentes de variación es fundamental para entender cómo los bosques podrán enfrentarse al aumento de temperatura, y la mayor frecuencia y severidad de sequías e incendios en las regiones mediterráneas. Utilizamos un ensayo de procedencias de pino carrasco replicado en tres sitios de ambiente contrastado para estudiar la plasticidad de la serotinia y realizamos diferentes experimentos manipulativos para comprobar la existencia de factores endógenos que afectan a la apertura de sus conos. La serotinia varió entre los tres sitios, incluso descontando el efecto alométrico (menor serotinia a mayor tamaño del árbol) y se confirmó la variabilidad genética. Además, la duración de la serotinia en esta especie implica la asignación de agua a los conos a través de sus pedúnculos, sugiriendo la existencia de costes de mantenimiento. Confirmando nuestras hipótesis, los ambientes desfavorables para el crecimiento de esta especie provocaron la liberación precoz de semillas, como efecto directo del ambiente además del propio estatus fisiológico del árbol. Estos resultados sugieren un riesgo en resiliencia de los pinares de pino carrasco bajo los nuevos escenarios de cambio climático.Agradecemos la asistencia técnica de E. Ballesteros, F. del Caño, R. Pulido y S. Sansegundo. Este trabajo ha sido financiado por los proyectos FENOPIN (AGL2012-40151-C03-02) y FUTURPIN (AGL2015-68274-C3-01). El Ministerio Español de Economía y Competitividad también financia al autor R.M.S. mediante una beca predoctoral (FPI BES-2013-064210). Algunos de los datos usados en este trabajo forman parte de la red nacional de ensayos genéticos forestales GENFORED (www.genfored.es)

Data from: Convergent and correlated evolution of major life-history traits in the angiosperm genus Leucadendron (Proteaceae)

Natural selection is expected to cause convergence of life histories among taxa as well as correlated evolution of different life-history traits. Here, we quantify the extent of convergence of five key life-history traits (adult fire survival, seed storage, degree of sexual dimorphism, pollination mode, and seed-dispersal mode) and test hypotheses about their correlated evolution in the genus Leucadendron (Proteaceae) from the fire-prone South African fynbos. We reconstructed a new molecular phylogeny of this highly diverse genus that involves more taxa and molecular markers than previously. This reconstruction identifies new clades that were not detected by previous molecular study and morphological classifications. Using this new phylogeny and robust methods that account for phylogenetic uncertainty, we show that the five life-history traits studied were labile during the evolutionary history of the genus. This diversity allowed us to tackle major questions about the correlated evolution of life-history strategies. We found that species with longer seed-dispersal distances tended to evolve lower pollen-dispersal distance, that insect-pollinated species evolved decreased sexual dimorphism, and that species with a persistent soil seed-bank evolved toward reduced fire-survival ability of adults