Leaf shape displays remarkable diversity, with its evolution hypothesized to reflect adaptive ecophysiological functions. Theoretical models propose that variation in leaf shape-particularly through modifications in effective leaf width (we)-primarily influences thermoregulation and hydraulic efficiency. However, comprehensive empirical tests of these hypotheses are lacking. Oxytropis diversifolia E. Peter (Fabaceae) has natural variation in leaf shape (1 leaflet, 1-3 leaflets, and 3 leaflets) and exhibits clinal variation, making it an ideal candidate to test those functional relationships. Here, we quantified leaf morphometrics across populations, logged in situ leaf temperature and gas exchange, and examined leaf anatomy associated with water balance. We confirmed that the production of more leaflets did reduce we. While leaves with reduced we could stay cooler during the day, the extent of leaf-to-air temperature difference was typically small (often within 1°C), suggesting a limited biological impact. Crucially, we identified a key anatomical trade-off in water relations: reduced we yielded beneficial lower chlorenchyma-to-midrib ratios and higher vein density, but at the cost of smaller vascular dimensions. This trade-off likely underpins the observed, context-dependent superior gas exchange of the intermediate phenotype. We propose that the functional significance of leaf shape lies in water relations over thermoregulation, with balancing selection on the anatomical trade-off providing a plausible mechanism maintaining the polymorphism.

The use of medicinal plants in Morocco has a long history and plays an important role in health care of the Moroccan population. This study is one of the first ethnobotanical studies that compare the ethnomedicinal knowledge of two types of expert informants on medicinal and aromatic plants conducted in contrasted regions of Morocco. It documented medicinal plant uses in three provinces (Meknes, Fez and Taounate) using semi-structured interviews. Overall,85 herbalists and 78 cooperative directors shared their knowledge of 151 plant species belonging to 64 families. This study revealed a rich diversity of medicinal plants in the three studied provinces, with a remarkable distinction in knowledge between herbalists and cooperative directors. Concerning the species used, the Asteraceae (16spp.), Lamiaceae (14spp.), Apiaceae (13spp.) and Fabaceae (10spp.) were the dominant families. Origanum compactum Benth was the most cited species (95%). Respiratory system diseases were the most frequent targets of the medicinal plants used (Informant agreement ratio= 0.95), whereas musculoskeletal system disorders were the lowest (0.81). This study can help identify those medicinal plants with the highest importance and utilization in these provinces. This information can hopefully be of interest to both future researchers, for pharmacological testing and conservation, and policy makers to better improve the medicinal plant research and assist those working in this sector.

In the current context of global changes, threatened flora is declining and homogenising at the expense of rare and protected species. Among conservation biology and ecological restoration techniques, plant translocation is one of the recommendations increasingly used. However, translocation remains risky and is recommended as a last resort to conserve protected flora in land use planning. Furthermore, it raises ethical questions partly linked to genetic processes. In this context, we studied how plant translocations are perceived by conservation actors in France, including their genetic aspects. The analysis of translocation perception complements that of feedback on concrete translocation operations and allows us to provide a qualitative assessment of current practices. We have adopted an interdisciplinary approach to survey different types of actors in nature conservation, involved or not in at least one stage of translocation operations (preparation, implementation and monitoring). Three main types of translocation perception divide our sample quite strongly (50

Since the first half of the twentieth century, evolutionary theory has been dominated by the idea that mutations occur randomly with respect to their consequences 1 . Here we test this assumption with large surveys of de novo mutations in the plant Arabidopsis thaliana . In contrast to expectations, we find that mutations occur less often in functionally constrained regions of the genome—mutation frequency is reduced by half inside gene bodies and by two-thirds in essential genes. With independent genomic mutation datasets, including from the largest Arabidopsis mutation accumulation experiment conducted to date, we demonstrate that epigenomic and physical features explain over 90% of variance in the genome-wide pattern of mutation bias surrounding genes. Observed mutation frequencies around genes in turn accurately predict patterns of genetic polymorphisms in natural Arabidopsis accessions ( r = 0.96). That mutation bias is the primary force behind patterns of sequence evolution around genes in natural accessions is supported by analyses of allele frequencies. Finally, we find that genes subject to stronger purifying selection have a lower mutation rate. We conclude that epigenome-associated mutation bias 2 reduces the occurrence of deleterious mutations in Arabidopsis , challenging the prevailing paradigm that mutation is a directionless force in evolution.

Small demographic size and reduced genetic diversity increase the extinction probability of a population. Genetic diversity within populations for neutral markers is an heuristic parameter, as it reflects past and ongoing processes acting on populations, and informs on possible futures. This study presents a synthesis of the knowledge on neutral genetic diversity for threatened plants in metropolitan France and the use of such data in management actions. Pairing threatened species with the closest non-threatened species for which we could find appropriate genetic data, we collected information on genetic diversity for 25 threatened species and non-threatened controls. We found that threatened species in France have on average a lower within-population genetic diversity than non-threatened controls and thus are exposed to risks linked to genetic erosion. Combining an analysis of recovery plans and a survey addressed to practitioners, we concluded that genetic diversity is rarely integrated in management actions. The integration of such information into applied conservation remains a challenge. We provide some guidelines to collect biological traits impacting within-population genetic diversity and some specific recommendations for a better incorporation of population genetics concepts into conservations actions.

PREMISE As part of global change, climate warming and pollinator decline are expected to affect plant phenology and plant-pollinator interactions. This paper aims at characterizing rapid evolution of life history traits and floral traits over two decades in the wild pansy (Viola arvensis), a common weed in agrosystems. METHODS We used a resurrection ecology approach with genotypes sampled in 1991 and 2012 from a population in Burgundy (France). The species has a mixed mating system (hereafter: mixed selfer) and presents a floral polymorphism. To correct for maternal effects, we measured plant traits in the second generation in a common garden (after a refreshing generation) to characterize plant evolution during the two decades. In addition, historical population selfing rates in 1991 and 2012 were inferred from microsatellites markers through heterozygote deficiency and identity disequilibrium. RESULTS Phenotypic data revealed a significant advance in flowering date, reduced flower sizes and a higher propensity of plants to set seed by autonomous selfing. Moreover, we detected a change in color morph frequency with an increase of the pale morph frequency. In accordance with phenotypic data, the neutral genetic data revealed an increase in historical selfing rates from 0.68 in 1991 to 0.86 in 2012. CONCLUSIONS Taken together, such data suggest that the wild pansy, a mixed selfer, is evolving a selfing syndrome that may be the consequence of reduced pollinator activity in agrosystems.

Iris lutescensis a common species occurring mainly in dry limestone habitats in Western Italy, Southern France, and Spain. The species shows a remarkable polymorphism for flower colour, and yellow and purple flowers can be found in the same population. As the species is a deceptive one, the previous studies on the maintenance of such a polymorphism were linked to its pollination ecology. Here, I reported on the spatial distribution of the polymorphism and showed that Spanish populations are mostly purple monomorphic. In contrast, populations in the South of France and Italy show the complete range, from 0 to 1, for the frequency of yellow morph, and the spatial autocorrelation for morph frequencies is very low. To go further, correlations between morph frequencies and abiotic factors, such as bioclimatic variables, UV irradiance, and aridity, were studied. On the whole, the spatial distribution of the frequency of yellow morph can be hardly explained by the contributions of these abiotic variables, and historical contingencies, including the phylogeography of the species have to be invoked, in particular, to explain the absence of polymorphic populations in Spain.

Global change is expected to drive short-term evolution of natural populations. However, it remains unclear whether different populations are changing in unison. Here, we study contemporary evolution of growth-related and reproductive traits of three populations of Cyanus segetum facing warming and pollinator decline across a latitudinal gradient in France. We resurrected stored seeds sampled up to 24 years apart from northern, central-western, and southern populations and conducted an in situ common-garden experiment. To disentangle neutral from selection-driven differentiation, we calculated neutral genetic differentiation (FST ) and quantitative trait differentiation (QST ) between temporal samples. We found that phenotypic evolution was divergent across populations exhibiting different trends for rosette size, date of flowering, and capitula size. By measuring seed set as a proxy of fitness, we showed that samples with larger mean capitula size outperformed samples with smaller mean capitula size in the western and southern populations. Regression of traits on seed set showed that flowering date and capitula size are the primary determinants of fitness, and QST -FST comparisons indicated that natural selection has likely contributed to the shifts in flowering phenology and rosette size. These findings outline the potential for rescue of natural populations through contemporary evolution and emphasize the complex interplay between spatial and temporal variation in species' responses to global change.

Little is empirically known about the contribution of mutations to fitness in natural environments. However, Fisher's Geometric Model (FGM) provides a conceptual foundation to consider the influence of the environment on mutational effects. To quantify mutational properties in the field, we established eight sets of MA lines (7-10 generations) derived from eight founders collected from natural populations of Arabidopsis thaliana from French and Swedish sites, representing the range margins of the species in Europe. We reciprocally planted the MA lines and their founders at French and Swedish sites, allowing us to test predictions of FGM under naturally occurring environmental conditions. The performance of the MA lines relative to each other and to their respective founders confirmed some and contradicted other predictions of the FGM: the contribution of mutation to fitness variance increased when the genotype was in an environment where its fitness was low, that is, in the away environment, but mutations were more likely to be beneficial when the genotype was in its home environment. Consequently, environmental context plays a large role in the contribution of mutations to the evolutionary process and local adaptation does not guarantee that a genotype is at or close to its optimum.

*Botanical Garden, School of Plant Sciences and Food Security, Tel Aviv University, Tel Aviv, Israel; †US Department of Agriculture, Agricultural Research Service, Madison, Wisconsin, USA; ‡School of Biological Sciences, Illinois State University, Normal, Illinois, USA; §Institut des Sciences de l0Évolution, Centre National de la Recherche Scientifique, University of Montpellier, Montpellier, France; and ∥Department of Botany and Biodiversity Research, University of Vienna, Vienna, Austria

Eryngium viviparum (Apiaceae) is an endangered endemic plant of the Atlantic region of Europe, growing in seasonally flooded sites, and is characterized by a highly disjunct distribution. It occurs in just a few sites in the north-western part of the Iberian Peninsula and in a single locality in France. To improve the conservation status of E. viviparum in France, a conservation programme has been implemented to reintroduce the species. Before considering such an operation, genetic studies were conducted to determine the genetic status of the last French population and to identify the genetic source that should be considered for the best reintroduction strategy. Using microsatellite markers, we documented the genetic structure of the last French population and compared its genetic diversity with that of ten Iberian populations, which cover the three geographical regions where the species occurs. As expected, the French population of E. viviparum shows low genetic diversity due to a bottleneck and geographical isolation. The evolutionary potential appears low, with no private alleles in this population. Furthermore, this population is highly differentiated from the Iberian populations in terms of genetic variation and ecological niche. These results bring new questions regarding the conservation of E. viviparum in France, especially for management and reintroduction aimed at favouring genetic diversity and avoiding extinction.

Climate change is a growing threat for global biodiversity, in particular for narrow endemic species. The Mediterranean region, which harbors an exceptional biodiversity, has been identified as one of the most sensitive regions to climate change. Based on a 22-year monitoring period, we analyzed the dynamic and viability of the six extant populations of a narrow endemic plant species of the Mediterranean area, Centaurea corymbosa, to predict their fate under two climatic scenarios. We constructed matrix projection models to calculate current asymptotic growth rates and to perform stochastic projections including both demographic and environmental stochasticity. Neither asymptotic growth rates nor their temporal variance were linked to population size and age at flowering. Randomization tests showed that asymptotic growth rates were significantly different among years but not among populations. An increase in temperature and a decrease in the number of wet days had a negative impact on the whole life-cycle, particularly in the summer period, and thus reduced asymptotic growth rates. Stochastic projections showed that an increased frequency of extreme climatic events increased population extinction risk and decreased mean time to extinction. The warm scenario had a more dramatic impact on population viability than the dry scenario. Management recommendations are proposed to increase population viability of endangered plant species such as C. corymbosa that face climate change.

Chaque annee 900 a 1000 etudiants sont inscrits dans le portail MONOD de l’UE Biologie Integrative des organismes. Le departement Biologie-Ecologie a fait le choix de favoriser l’enseignement pratique pour favoriser l’apprentissage. Cette UE de 5 ECTS compte donc 30h de TP, 10.5h de TD pour 9h de CM. L’enjeu de cette UE est de sensibiliser les etudiants a toutes les facettes de la biologie tout en leur faisant acquerir, par la pratique, un certain nombre d’apprentissage basiques specifiques a la biologie (reconnaitre et classer les organismes avec les methodes dediees…) et des competences plus transversales : rediger un compte-rendu d’observation, faire un diagramme de manipulation tout en respectant un horaire. Le premier verrou est donc de faire acquerir de nombreuses competences a differents niveaux et dans le meme temps. A cela s’ajoute le nombre et la diversite des profils etudiants mais aussi le nombre et la diversite des profils enseignants. Savoir rediger un compte-rendu d’observation et d’experimentation est une competence essentielle pour un scientifique et suit la logique de redaction d’une publication. L’objectif de notre etude a donc ete d’optimiser cet apprentissage et de pallier le manque d’uniformite a la fois sur la forme et le delai de rendu des corrections des comptes rendus. De plus, les corrections des enseignants sont souvent incomprises et mal vecues. L’autoevaluation et l’evaluation par les pairs semblent des methodes qui permettent aux etudiants de mieux comprendre les attendus. Dans l’autoevaluation, l’etudiant est face a lui-meme et n’a pas a craindre de l’image qu’il renvoie. L’evaluation par les pairs permet une relation apprenant-apprenant. On n’est pas dans un rapport hierarchique. Par contre, la crainte du regard de l’autre peut-etre un biais. L’anonymat est une solution pour pallier ce biais. Utiliser cette methode via une interface informatique de type Moodle permet la mise en place d’une uniformisation plus controlee, et un parametrage facilite de la repartition, de l’anonymat et de la notation. Elle necessite en prealable une bonne pratique des outils de bureautique par les etudiants. Notre objectif a donc ete d’utiliser la plateforme Moodle pour utiliser l’outil atelier a la fois pour l’autoevaluation des 2 premiers TP et l’evaluation par les pairs du TP3, suivi d’une evaluation classique par l’enseignant pour le TP4. Nous avons beneficie pour cela d’un soutien de la Faculte des Sciences de l’universite de Montpellier via l’appel a projet TICE 2016-2017. Nos resultats concernent a la fois l’appreciation des etudiants pour cet outil mais aussi le bilan sur l’evolution des notes au cours de l’annee et en comparaison avec les promotions des annees precedentes n’ayant pas eu ce dispositif. Cet outil ne peut que perdurer s’il a l’adhesion a la fois des etudiants et des enseignants. Nos resultats montrent que les etudiants sont majoritairement favorables a cet outil s’il est utilise tot dans l’apprentissage. Le retour des enseignants est plus heterogene notamment sur le fait d’integrer cette evaluation dans la moyenne de l’UE. Nous commenterons aussi l’outil, l’avantage et l’inconvenient des differents parametres testes mais aussi le temps de gestion en regard de l’utilisation de cet outil. Enfin, nous proposerons des perspectives d’amelioration afin d’optimiser son utilisation. En effet, la mise en place et la maintenance est assez lourde durant l’operation. Une sensibilisation des enseignants et une formation a l’outil permettrait de tirer tous les avantages de cet outil.

The admixture and recombination of individuals from the native range into a new range may lead to the production of invasive genotypes that have higher fitness and wider climatic tolerances than the native genotypes.In this paper, we compare the survival and growth of native EU and invasive NA genotypes when planted back into the native EU range near where the EU genotypes were collected.We test this hypothesis using the invasive wetland grass Phalaris arundinacea.If invasive genotypes have evolved to have higher survival and growth, then they should outperform the native EU genotypes under field conditions that are better suited to the EU genotypes.Individual plants of the wetland grass, Phalaris arundinacea collected from native Europe (Czech Republic (CZ) and France (FR)) and North America (Vermont (VT) and North Carolina (NC)) were planted into common gardens in Trebon, Czech Republic (49.0042˚N, 14.7721˚E) and Moussac, France (43.9808˚N, 4.2241˚E).Invasive genotypes from North Carolina (NC) survived as well or better than native genotypes in both the Trebon and Moussac garden.Additionally, invasive NC genotypes suffered higher herbivore damage than native genotypes but their growth and survival were not significantly different than genotypes from the other regions.A companion field experiment that simulated biomass removal through grazing indicated that invasive NC genotypes recovered faster following grazing than genotypes from other regions.Our results suggest that not all invasive genotypes are superior and regional differences in aggressiveness between invasive genotypes are as great as differences between individu-How to cite this paper:

Plant–pollinator interactions are believed to play a major role in the evolution of floral traits. Flower colour and flower size are important for attracting pollinators, directly influencing reproduction, and thus expected to be under pollinator‐mediated selection. Pollinator‐mediated selection is also proposed to play a role in maintaining flower colour polymorphism within populations. However, pigment concentrations, and thus flower colour, are also under selective pressures independent of pollinators. We quantified phenotypic pollinator‐mediated selection on flower colour and size in two colour polymorphic Iris species. Using female fitness, we estimated phenotypic selection on flower colour and size, and tested for pollinator‐mediated selection by comparing selection gradients between flowers open to natural pollination and supplementary pollinated flowers. In both species, we found evidence for pollen limitation, which set the base for pollinator‐mediated selection. In the colour dimorphic Iris lutescens, while pigment concentration and flower size were found to be under selection, this was independent of pollinators. For the polymorphic Iris pumila, pigment concentration is under selective pressure by pollinators, but only for one colour morph. Our results suggest that pollinators are not the main agents of selection on floral traits in these irises, as opposed to the accepted paradigm on floral evolution. This study provides an opposing example to the largely‐accepted theory that pollinators are the major agent of selection on floral traits.

Background and Aims Speciation is often described as a continuous dynamic process, expressed by different magnitudes of reproductive isolation (RI) among groups in different levels of divergence. Studying intraspecific partial RI can shed light on mechanisms underlying processes of population divergence. Intraspecific divergence can be driven by spatially stochastic accumulation of genetic differences following reduced gene flow, resulting in increased RI with increased geographical distance, or by local adaptation, resulting in increased RI with environmental difference. Methods We tested for RI as a function of both geographical distance and ecological differentiation in Iris atropurpurea, an endemic Israeli coastal plant. We crossed plants in the Netanya Iris Reserve population with plants from 14 populations across the species' full distribution, and calculated RI and reproductive success based on fruit set, seed set and fraction of seed viability. Key Results We found that total RI was not significantly associated with geographical distance, but significantly increased with ecological distance. Similarly, reproductive success of the crosses, estimated while controlling for the dependency of each component on the previous stage, significantly reduced with increased ecological distance. Conclusions Our results indicate that the rise of post-pollination reproductive barriers in I. atropurpurea is more affected by ecological differentiation between populations than by geographical distance, supporting the hypothesis that ecological differentiation is predominant over isolation by distance and by reduced gene flow in this species. These findings also affect conservation management, such as genetic rescue, in the highly fragmented and endangered I. atropurpurea.

Methods Genetic diversity levels and population genetic structure were investigated through the genotyping of a collection of 1120 individuals in 41 populations ranging from Spain to France, using a set of eight newly developed microsatellite markers. In addition, phenotypic differentiation for flower colour was also quantified by counting colour morph frequency in each population, and measuring the reflectance spectra of sampled individuals.Key Results Populations in Spain present a sharp colour transition from solely purple to solely yellow. The results provide evidence that genetic drift through limited gene flow is important in the evolution of monomorphic populations. In contrast, most populations in France are polymorphic with both phenotypes, and the colour frequencies vary geographically without any spatial gradients observed. A pattern of isolation by distance is detected in France, and gene flow between adjacent populations seems to be an important factor maintaining populations polymorphic.Conclusions Overall, neutral processes contribute to patterns of spatial variation for flower colour in I. lutescens, but it cannot be excluded that natural selection is also operating. An interaction between neutral processes and natural selection is suggested to explain the spatial variation for flower colour in I. lutescens.

Among the diversity of pollination strategies, food deception is intriguing because of the lack of rewards offered for the pollination services. Floral food deception has been frequently recorded in orchids; however, there is little evidence for food deception outside the Orchidaceae. One putative non-orchid candidate is the Mediterranean Iris lutescens, which displays an heritable polymorphism for flower colour, with yellow and purple morphs. Colour polymorphism is frequently thought to be maintained by negative frequency-dependent selection, where rare morphs are visited more frequently than common ones. Here, we present data on reproductive biology and pollination ecology of the species in the light of the deceptive pollination strategy and the maintenance of flower colour polymorphism. There was no difference in sex allocation and flowering phenology between morphs, with a blooming period early in spring. Both colour morphs are equally self-incompatible and they depend on insects for seed production. The most common visitors with pollen loads are small and large Apoids. These were observed foraging for non-existent nectar (rather than pollen) on Iris flowers. Most of them appear to learn to avoid Iris flowers as classically observed for rewardless species, and there was no evidence of an advantage for the rare morph. Instead, we found that in some populations, large bee pollinators appeared to prefer the most common morph (positive frequency-dependent selection). Iris lutescens appears to be a hitherto neglected but relevant candidate to investigate deceptive reproductive strategy and selective pressures in generalist plants.