Effiiency of the Essential Oil of Porophyllum linaria (Asteraceae) a Mexican Endemic Plant Against Sitophilus zeamais (Coleoptera: Curculionidae).

The insecticidal and repellent effect of essential oil isolated from fresh leaves of Porophyllum linaria on maize weevil was evaluated, as well as the effect on the grain germination after treated. In total, 28 constituents were identified by gas chromatography coupled with mass spectrometry accounting for 99.86% of whole essential oil. The main majority compounds were ß-myrcene (41.94%), D-limonene (20.29%), and estragole (20.03%). Contact toxicity significantly increased with dose and time after treatment. With the 800 ppm (highest concentration), the mortality (%) obtained for the tenth and fifteenth day was 43 and 82%, respectively, whereas with 50 ppm (lowest concentration) 30% mortality was obtained at the end of the experiment (fifteenth day). At 15 d (end of the experiment), the LC50 y LC90 were obtained with values of 329.01 ± 44.35 y 1058.86 ± 117.76 ppm, respectively. For a concentration of 800 ppm, a selection index of zero was obtained, indicating the preference of the pest to the untreated maize (control). The maize grains germination test showed a significant reduction both in the length of hypocotyl and radicle of maize grain. So, in the highest dose, the hypocotyl and radicle length was 1.40 ± 0.34 and 9.14 ± 0.55 cm, respectively, whereas the control group registered 3.28 ± 0.39 and 13.02 ± 0.97 cm, respectively. This finding is promising since as it could result in the identification of botanical substances capable of suppressing maize weevil, Sitophilus zeamais development.

Increased CG, CHG and CHH methylation at the cycloidea gene in the "Peloria" mutant of Linaria vulgaris.

Heritable DNA methylation variation is frequently observed in natural populations of plants, but is thought mostly to be functionally inconsequential. An exception to this is the "Peloria" mutant of Linaria vulgaris, which was originally described by Carl von Linné in 1744. A study in 1999 found that the Peloria phenotype is caused by an epiallele of the L. vulgaris cycloidea homolog Lcyc that showed increased levels of DNA methylation compared to wild-type. The DNA methylation results in silencing of Lcyc, which causes radial flower symmetry in the peloric mutant, whereas wild-type plants have flowers with bilateral symmetry. However, a detailed view of DNA methylation at Lcyc at the single-nucleotide level has not been available. In this study, we investigated DNA methylation at Lcyc and, as a control, at the LvHIRZ gene in wild-type and peloric plants of L. vulgaris using DNA bisulfite treatment coupled to next-generation sequencing. We found strong increases in CHG and CHH methylation at Lcyc, but not LvHIRZ, in Peloria. CG methylation was also increased, but wild-type Lcyc also showed moderate levels of CG methylation. Our results suggest that DNA methylation in all three sequence contexts has been maintained, and potentially transgenerationally inherited, in the peloric L. vulgaris population over decades or even centuries.

New insight into antimicrobial activities of Linaria ventricosa essential oil and its synergetic effect with conventional antibiotics.

The purpose of the present study was to determine for the first time the volatile constituents, the antioxidant and antimicrobial activities of the essential oil (EO) of the endemic Moroccan Linaria ventricosa, alone or in combination with four known antibiotics. The major constituents were 2-methoxy-4-vinylphenol (17.4%), α-terpinene (13.64%) and 3,5-dimethylphenyl isocyanate (12.21%). The EO had moderate antioxidant potency, as measured by DPPH free radical scavenging (1.233 ± 0.031 mg/mL), ferric reducing antioxidant power assay (0.373 ± 0.019 mg/mL) and ß-carotene/linoleic acid (0.922 ± 0.026 mg/mL). EO showed microbicidal activity against all microorganisms tested. The highest effectiveness was recorded against Candida albicans (IZ = 24 mm, MIC = 4.87 mg/mL and MMC = 9.75 mg/mL) and Candida glabrata (IZ = 22 mm, MIC = MMC = 4.87 mg/mL). Gram negative bacteria were the most resistant (MIC = MMC = 39 mg/mL). The combination of EO at sub-inhibitory concentrations with antibiotics showed a significant decrease in their individual MICs from 2 to 128 fold, being the best for ciprofloxacin and fluconazole against E. coli and C. albicans and C. glabrata, respectively.

Chemical composition, in vitro antioxidant, anticholinesterase and antibacterial activities of Linaria scariosa Desf.

The study was performed on the dichloromethane (DCM), ethyl acetate (EAc) and n-butanol (Bu) fractions (F) obtained from the 80% ethanol extract of Linaria scariosa Desf. aerial parts, collected in the North Eastern region of Algeria. Remarkable total phenolic and flavonoid contents were obtained, mainly for EAcF. These results were in accordance with the antioxidant activity of EAcF against DPPH, ABTS, CUPRAC and reducing power tests. DCMF and BuF exhibited significant cholinesterase activity inhibition of BChE and AChE. Moreover, EAcF displayed only moderate antibacterial activities, especially against S. aureus. The biological results were correlated to the chemical components, deduced by both GC-MS analysis of the fractions and the isolation of hemipholin, pectolinarigenin, antirride, antirrinoside, pectolinarin and linariosise, some of which known to exhibit potent effects on the tested biological activities. The study provides the first biological and chemical investigation on Linaria scariosa Desf (unresolved name).

Anti-inflammatory and hemostatic effects of Linaria reflexa Desf.

The work presented here was aimed to investigate the in vivo anti-inflammatory and in vitro hemostatic activities of Linaria reflexa extract and to establish the relationship between its bioactivity and chemical composition. Twenty-three secondary metabolites were identified, most of them are good anti-inflammatory agents, in line with data by carrageenin-induced rat paw edema assays of the n-butanol extract showing high anti-inflammatory inhibition (63.90%) of edema swelling in the rat paw at the dose 200 mg/kg after 4 h. Furthermore, both extent of inflammatory response and tissue injury were prevented keeping the levels of rate myeloperoxidase (60.16%) and of malondialdehyde, which is the final product of lipid peroxidation generated by free radicals (58.58%). The same extract showed also a remarkable hemostatic effect established by measuring the coagulation time of decalcified plasma (45 s), related to its flavonoid glycosides content.

Linaburiosides A-D, acylated iridoid glucosides from Linaria buriatica.

Four previously undescribed acylated iridoid glucosides, linaburiosides A‒D, one undescribed iridoid, 7-deoxyiridolactonic acid, and one known acylated iridoid glucoside, iridolinarin C, were isolated from the aerial parts of a Mongolian traditional herbal medicine, Linaria buriatica. Linaburiosides A‒D had an acyl moiety corresponding to 7-deoxyiridolactonic acid. Detailed spectroscopic analyses of linaburiosides A‒D and 7-deoxyiridolactonic acid led to the assignment of their structures. The absolute configuration of 7-deoxyiridolactonic acid was elucidated by application of the PGME method; those of linaburiosides A‒D were assigned on the basis of chemical conversions, as well as application of the modified Mosher's method. The absolute configuration of iridolinarin C was also elucidated in this study. Anti-inflammatory and antiproliferative activities of isolated compounds and their derivatives were evaluated.

Summer Development and Survivorship of the Weed Biocontrol Agent, Mecinus janthiniformis (Coleoptera: Curculionidae), Within Stems of Its Host, Dalmatian Toadflax (Lamiales: Plantaginaceae), in Utah.

The summer phenology and survivorship of the stem-mining weevil, Mecinus janthiniformis Tosevski and Caldara, a biocontrol agent of Dalmatian toadflax, Linaria dalmatica (L.) Miller, was studied in 2015-2016 as it developed within host plant stems at a low elevation, open rangeland site in northern Utah. Hatching from eggs in spring and early summer, weevils occurred as larvae within stems in June. Earliest maturing adults occurred in mid-July, and the majority of individuals had completed pupal development by early August. Survivorship within stems was high, with two-thirds or more of individuals surviving from egg hatch to adulthood as assessed in mid-September. Mortality rates within stems were highest during larval development, with parasitism accounting for the majority of deaths. At least three parasitoid species (Chalcidoidea: Pteromalidae and Eupelmidae), including both endoparasitoids and ectoparasitoids, were found attacking weevils within stems. Although most surviving weevils remained as adults within stems to overwinter, some adults were found to have chewed exit holes, and in some cases had exited from stems, beginning in July; the fate of these prematurely exiting adults is unknown. Low summer mortality rates within stems should promote weevil establishment under the hot, dry conditions of northern Utah, but parasitism and premature exiting of adults from host stems merit further investigation concerning their potential to reduce biocontrol efficacy. The results presented here for M. janthiniformis phenology within host stems will contribute to the development of standardized, summer monitoring for this biocontrol agent by stem dissection.

Rapid loss of self-incompatibility in experimental populations of the perennial outcrossing plant Linaria cavanillesii.

Transitions from self-incompatibility to self-compatibility in angiosperms may be frequently driven by selection for reproductive assurance when mates or pollinators are rare, and are often succeeded by loss of inbreeding depression by purging. Here, we use experimental evolution to investigate the spread of self-compatibility from one such population of the perennial plant Linaria cavanillesii into self-incompatible (SI) populations that still have high inbreeding depression. We introduced self-compatible (SC) individuals at different frequencies into replicate experimental populations of L. cavanillesii that varied in access to pollinators. Our experiment revealed a rapid shift to self-compatibility in all replicates, driven by both greater seed set and greater outcross siring success of SC individuals. We discuss our results in the light of computer simulations that confirm the tendency of self-compatibility to spread into SI populations under the observed conditions. Our study illustrates the ease with which self-compatibility can spread among populations, a requisite for species-wide transitions from self-incompatibility to self-compatibility.

Macroevolutionary dynamics of nectar spurs, a key evolutionary innovation.

Floral nectar spurs are widely considered a key innovation promoting diversification in angiosperms by means of pollinator shifts. We investigated the macroevolutionary dynamics of nectar spurs in the tribe Antirrhineae (Plantaginaceae), which contains 29 genera and 300-400 species (70-80% spurred). The effect of nectar spurs on diversification was tested, with special focus on Linaria, the genus with the highest number of species. We generated the most comprehensive phylogeny of Antirrhineae to date and reconstructed the evolution of nectar spurs. Diversification rate heterogeneity was investigated using trait-dependent and trait-independent methods, and accounting for taxonomic uncertainty. The association between changes in spur length and speciation was examined within Linaria using model testing and ancestral state reconstructions. We inferred four independent acquisitions of nectar spurs. Diversification analyses revealed that nectar spurs are loosely associated with increased diversification rates. Detected rate shifts were delayed by 5-15 Myr with respect to the acquisition of the trait. Active evolution of spur length, fitting a speciational model, was inferred in Linaria, which is consistent with a scenario of pollinator shifts driving diversification. Nectar spurs played a role in diversification of the Antirrhineae, but diversification dynamics can only be fully explained by the complex interaction of multiple biotic and abiotic factors.

Resource allocation in response to herbivory and gall formation in Linaria vulgaris.

Trehalose and its precursor, trehalose 6-phosphate (T6P), are essential regulators of plant response to abiotic and biotic stress. Here we used the specific host-insect interaction between Linaria vulgaris (Plantaginaceae) and stem-galling weevil, Rhinusa pilosa (Mecinini, Curculionidae) with the aim to distinguish carbohydrate allocation patterns in response to herbivory, gall formation (G1, 24 h after oviposition), and gall development (G2, 7 days after oviposition) under controlled conditions. The hypothesis is that herbivory and galling induce distinct responses in both leaves and stems, and that shifts in carbon allocations are regulated by signaling sugars. Systemic response to herbivory was accumulation of T6P and maltose. The main feature of G1 in the stems was accumulation of trehalose, accompanied by increased T6P, turanose and glucose content, oppositely to the leaves. In G2, galls had 3-folds higher weight than controls, with further accumulation of fructose, glucose, turanose, and total water-insoluble carbohydrates (TIC), while the sucrose/hexose ratio decreased. Analysis of fast chlorophyll fluorescence kinetic (OJIP) transients in G2 showed a slight decrease in quantum yield of electron transport flux from QA to QB, and towards photosystem I acceptor side, correlated with the decreased content of photosynthetic pigments and hexoses accumulation. Redistribution of photosynthates, and accumulation of T6P were induced in response to herbivory, indicating its signaling role. The results support the hypothesis that R. pilosa can induce plant reprogramming towards the accumulation of beneficial carbohydrates in developing gall by mechanisms which include both T6P and trehalose.

The flavonoid acetylpectolinarin counteracts the effects of low ethanol on spontaneous network activity in hippocampal cultures.

ETHNOPHARMACOLOGICAL RELEVANCE: A major concern in modern society involves the lasting detrimental behavioral effects of exposure to alcoholic beverages. Consequently, hundreds of folk remedies for hangover have been suggested, most of them without a scientific basis, for lack of proper test systems. Over centuries, yellow toadflax (Linaria vulgaris Mill., Lv) tincture has been used in Russian traditional medicine to treat the spectrum of hangover symptoms such as vertigo, headache, drunken behaviors, and as a sedative. MATERIALS AND METHODS: Here we use in-vitro cultured hippocampal neurons to examine the effect of the Lv extract as well as the flavonoid acetylpectolinarin (ACP) exclusively found in Lv extract, on spontaneous network activity of the cultured neurons exposed to low, physiological concentrations of ethanol. RESULTS: As in previous studies, low (0.25-0.5%) ethanol causes an increase in network activity, which was converted to suppression, with high concentrations of ethanol. Lv extract and ACP, at low concentrations, had no appreciable effect on spontaneous activity, but they blocked the facilitating action of low ethanol. This action of ACP was also seen when the culture was exposed to 1-EBIO, a SK potassium channel opener, and was blocked by apamin, an SK channel antagonist. In contrast, ACP or Lv extracts did not reverse the suppressive effects of higher ethanol. CONCLUSIONS: Our results suggest that ACP acts by interacting with the SK channel, to block the facilitatory effect of low concentration of ethanol, on network activity in hippocampal cultures.

Allergy-preventive effects of linarinic acid and its tetrahydropyrrolo[2,1-b]quinazoline derivatives isolated from Linaria vulgaris.

Linarinic acid, (-)-1,2,3,9-tetrahydropyrrolo[2,1-b]quinazoline-1-carboxylic acid (4a), was isolated from the ethanol extract of Linaria vulgaris Mill. In our previous study, a series of tetrahydropyrrolo[2,1-b]quinazoline derivatives 4b, 4c, 5a, 5b, 6a and 6b that were structurally related to 4a and evaluated as neuroprotective agents were synthesized. The aim of the present study was to investigate the novel features of these compounds. We examined their allergy-preventive effects using an in vivo assay system we developed previously, that monitors a decrease in blood flow in the tail vein of mice subjected to sensitization with hen egg-white lysozyme. We observed that 4a and its three derivatives, amide (6a), ester (5a), bromine (4b), and alcohol substituent (6b), showed significant allergy-preventive activities. The study confirmed the allergy-preventive activity of tetrahydropyrrolo[2,1-b]quinazoline derivatives by comprehensively monitoring the specific blood flow decrease occurring in the induction phase of allergy. This finding may aid in the development of new agents for the treatment of allergic diseases such as atopic dermatitis, allergic asthma, and hay fever.

Evolution of nectar spur length in a clade of Linaria reflects changes in cell division rather than in cell expansion.

Background and Aims: Nectar spurs (tubular outgrowths of a floral organ which contain, or give the appearance of containing, nectar) are hypothesized to be a 'key innovation' which can lead to rapid speciation within a lineage, because they are involved in pollinator specificity. Despite the ecological importance of nectar spurs, relatively little is known about their development. We used a comparative approach to investigate variation in nectar spur length in a clade of eight Iberian toadflaxes. Methods: Spur growth was measured at the macroscopic level over time in all eight species, and growth rate and growth duration compared. Evolution of growth rate was reconstructed across the phylogeny. Within the clade we then focused on Linaria becerrae and Linaria clementei, a pair of sister species which have extremely long and short spurs, respectively. Characterization at a micromorphological level was performed across a range of key developmental stages to determine whether the difference in spur length is due to differential cell expansion or cell division. Key Results: We detected a significant difference in the evolved growth rates, while developmental timing of both the initiation and the end of spur growth remained similar. Cell number is three times higher in the long spurred L. becerrae compared with L. clementei, whereas cell length is only 1.3 times greater. In addition, overall anisotropy of mature cells is not significantly different between the two species. Conclusions: We found that changes in cell number and therefore in cell division largely explain evolution of spur length. This contrasts with previous studies in Aquilegia which have found that variation in nectar spur length is due to directed cell expansion (anisotropy) over variable time frames. Our study adds to knowledge about nectar spur development in a comparative context and indicates that different systems may have evolved nectar spurs using disparate mechanisms.

Phenology of the Dalmatian Toadflax Biological Control Agent Mecinus janthiniformis (Coleoptera: Curculionidae) in Utah.

The phenology of the stem-mining weevil Mecinus janthiniformis Tosevski and Caldara (Coleoptera: Curculionidae) as adults attacking Dalmatian toadflax, Linaria dalmatica (L.) Miller (Plantaginaceae), was studied in 2014-2015 at two low elevation sites in northern Utah. The seasonal pattern of adult weevil abundance on the host plant at the two sites was most similar between years when described by degree-day accumulation, versus calendar date. Repeated censusing over the growing season revealed that males appeared first and subsequently peaked in abundance on the host plant earlier than females did, such that the adult population was dominated by males early in the season and by females late in the season. Peak female abundance on the host plant occurred at the time when Dalmatian toadflax stems reached their maximum height and density and when they began flowering widely. Maximum toadflax stem heights and densities, and flowering activity, were markedly reduced in 2015 compared to 2014. In contrast to these host plant parameters that vary between years, degree-day accumulation can be used readily for timing collection and survey efforts for adult weevils and female adult weevils in particular. Use of degree-day accumulation can thereby facilitate implementation of redistribution and monitoring programs for M. janthiniformis as a biological control agent of Dalmatian toadflax.

Resolving Recent Plant Radiations: Power and Robustness of Genotyping-by-Sequencing.

Disentangling species boundaries and phylogenetic relationships within recent evolutionary radiations is a challenge due to the poor morphological differentiation and low genetic divergence between species, frequently accompanied by phenotypic convergence, interspecific gene flow and incomplete lineage sorting. Here we employed a genotyping-by-sequencing (GBS) approach, in combination with morphometric analyses, to investigate a small western Mediterranean clade in the flowering plant genus Linaria that radiated in the Quaternary. After confirming the morphological and genetic distinctness of eight species, we evaluated the relative performances of concatenation and coalescent methods to resolve phylogenetic relationships. Specifically, we focused on assessing the robustness of both approaches to variations in the parameter used to estimate sequence homology (clustering threshold). Concatenation analyses suffered from strong systematic bias, as revealed by the high statistical support for multiple alternative topologies depending on clustering threshold values. By contrast, topologies produced by two coalescent-based methods (NJ$_{\mathrm{st}}$, SVDquartets) were robust to variations in the clustering threshold. Reticulate evolution may partly explain incongruences between NJ$_{\mathrm{st}}$, SVDquartets and concatenated trees. Integration of morphometric and coalescent-based phylogenetic results revealed (i) extensive morphological divergence associated with recent splits between geographically close or sympatric sister species and (ii) morphological convergence in geographically disjunct species. These patterns are particularly true for floral traits related to pollinator specialization, including nectar spur length, tube width and corolla color, suggesting pollinator-driven diversification. Given its relatively simple and inexpensive implementation, GBS is a promising technique for the phylogenetic and systematic study of recent radiations, but care must be taken to evaluate the robustness of results to variation of data assembly parameters.

The divergence history of the perennial plant Linaria cavanillesii confirms a recent loss of self-incompatibility.

Many angiosperms prevent inbreeding through a self-incompatibility (SI) system, but the loss of SI has been frequent in their evolutionary history. The loss of SI may often lead to an increase in the selfing rate, with the purging of inbreeding depression and the ultimate evolution of a selfing syndrome, where plants have smaller flowers with reduced pollen and nectar production. In this study, we used approximate Bayesian computation (ABC) to estimate the timing of divergence between populations of the plant Linaria cavanillesii that differ in SI status and in which SI is associated with low inbreeding depression but not with a transition to full selfing or a selfing syndrome. Our analysis suggests that the mixed-mating self-compatible (SC) population may have begun to diverge from the SI populations around 2810 generation ago, a period perhaps too short for the evolution of a selfing syndrome. We conjecture that the SC population of L. cavanillesii is at an intermediate stage of transition between outcrossing and selfing.

Flavonoids extracted from Linaria vulgaris protect against hyperlipidemia and hepatic steatosis induced by western-type diet in mice.

Previous studies have shown that flavonoids (Fs) present in Linaria vulgaris inhibit lipid accumulation in vitro. This study was designed to evaluate the effects of Fs extracted from Linaria vulgaris ssp. sinensis (Bebeaux) Hong, on hyperlipidemia and hepatic steatosis induced by a western-type diet in mice. The major constituents of Fs were analyzed by LC-MS analysis. C57BL/6 mice were fed a western-type diet for 8 weeks to induce hyperlipidemia (model group), or fed a western-type diet followed by Fs treatment (90, 30 or 10 mg/kg/day) or atorvastatin treatment (1.0 mg/kg/day), for 8 weeks. It was found that Fs treatment resulted in significant reductions in serum levels of AST, ALT, TC, TG, LDL-C, free fatty acid and hepatic TC, and TG compared to those in model mice with hyperlipidemia (P < 0.05). The mice treated with Fs showed a relatively normal hepatic architecture compared to the hepatic steatosis shown in the model group. Moreover, the expressions of mature forms of sterol regulatory element-binding proteins (nuclear form of srebps, n-SREBPs) and 3-hydroxy-3-methylglutaryl coenzyme reductase (HMGCR) involved in lipid metabolism, were suppressed in the Fs-treated groups. Taken together, these results suggest Fs exert protective effects against hyperlipidemia and hepatic steatosis, which may involve the inhibition of mature SREBPs expressions.

Iridoids and anti-inflammatory properties of n-butanol extract of Linaria tingitana Boiss. & Reut.

The analysis of the n-butanol extract of Linaria tingitana (BELT) by HPLC-DAD-ESI/MS allowed the identification of four iridoids structurally confirmed by NMR and ESI-MS/MS extensive experiments data. The subjection of BELT to the anti-inflammatory activity showed that it exhibited a concentration dependent stabilisation of HRBC membrane, inhibition of protein denaturation and nitric oxide scavenging effect in the in vitro process. These results were confirmed in the in vivo experiments which showed that BELT was found to be most pronounced at 200 mg/kg after carrageenan injection which significantly reduced the swelling in both early and late phases of carrageenan-evoked oedema, as well as a significant reduce at the accumulation of infiltrating cells, inhibition of the myeloperoxidase activity and suppressed the lipid peroxidation. These results were supported by the histological analysis which revealed the reduction of oedema and cells infiltration, this might be influenced by the synergistic action of the above isolated compounds.

Glycosyl flavonoid profile, in vivo antidiabetic and in vitro antioxidant properties of Linaria reflexa Desf.

Aerial parts of Linaria reflexa, used in North African folk medicine for treating certain skin diseases, were investigated by HPLC-DAD-ESI/MS technique able to identify the glycosyl flavonoids pectolinarin (1), isolinariin A (2), isolinariin B (3), linariin (4), isolinariin D (5) and isolinariin E (6) as the most abundant components in both hydroalcoholic (HAE) and ultrasound-assisted (UAE) extracts profiles. Metabolite 5, isolated and fully characterised by extensive nuclear magnetic resonance (NMR) analysis, has been very recently reported from L. japonica together with the compound 6. Good antioxidant activities (DPPH radical scavenging, ß-carotene bleaching and reducing power assays) were observed for the extracts. The remarkable antidiabetic activity displayed by UAE (300 mg/kg) has yielded the most marked decrease in blood glucose levels of the alloxan diabetic rats (-72.09%), greater than the effects by the drug glybenclamide (-63.29%). This study reports the first correlation of antidiabetic activity of Linaria sp. extracts with their chemical composition.

Maintenance of mixed mating after the loss of self-incompatibility in a long-lived perennial herb.

BACKGROUND AND AIMS: Many hermaphroditic plants avoid self-fertilization by means of a molecular self-incompatibility (SI) system, a complex trait that is difficult to evolve but relatively easy to lose. Loss of SI is a prerequisite for an evolutionary transition from obligate outcrossing to self-fertilization, which may bring about rapid changes in the genetic diversity and structure of populations. Loss of SI is also often followed by the evolution of a 'selfing syndrome', with plants having small flowers, little nectar and few pollen grains per ovule. Here, we document the loss of SI in the long-lived Spanish toadflax Linaria cavanillesii, which has led to mixed mating rather than a transition to a high rate of selfing and in which an outcrossing syndrome has been maintained. METHODS: We performed crosses within and among six populations of L. cavanillesii in the glasshouse, measured floral traits in a common-garden experiment, performed a pollen-limitation experiment in the field and conducted population genetic analyses using microsatellites markers. KEY RESULTS: Controlled crosses revealed variation in SI from fully SI through intermediate SI to fully self-compatible (SC). Flowers of SC individuals showed no evidence of a selfing syndrome. Although the SC population of L. cavanillesii had lower within-population genetic diversity than SI populations, as expected, population differentiation among all populations was extreme and represents an FST outlier in the distribution for both selfing and outcrossing species of flowering plants. CONCLUSIONS: Together, our results suggest that the transition to SC in L. cavanillesii has probably been very recent, and may have been aided by selection during or following a colonization bottleneck rather than in the absence of pollinators. We find little indication that the transition to SC has been driven by selection for reproductive assurance under conditions currently prevailing in natural populations.