Deciphering the ecology of the threatened microendemic species Euphorbia margalidiana

Small islands play a critical role in the study of plant ecology and evolution. Here, we reveal the ecology of Euphorbia margalidiana, an endemic plant that thrives in a micro-island environment in the Western Mediterranean region. Through a detailed characterization of the habitat, including plant communities, microclimate, soil properties, and germination assays, we examine the effects of biotic and abiotic factors on the distribution of this endangered species. We also analyze its pollination biology, evaluate the success of vegetative propagation, and discuss its potential use in conservation strategies. Our results show that E. margalidiana is a characteristic species of the shrub ornitocoprophilous insular vegetation of the Western Mediterranean. The seeds have a very low dispersion capacity outside the islet and that seed-derived plants have higher survival rates under drought conditions than those vegetatively propagated. The main volatile compound emitted from the pseudanthia is phenol which attracts the plants’ main and almost exclusive pollinators in the islet, flies. Our results confirm the relictual status of E. margalidiana and highlight the importance of key adaptive traits that enable the survival of this species in the harsh micro-island environment of Ses Margalides

Geographical and environment-related variations of essential oils in isolated populations of Thymus richardii Pers. in the Mediterranean basin

Composition of essential oils of different populations of Thymus richardii grex of six localities from Bosnia-Herzegovina (Konjic, Borci), Spain (Majorca, Ibiza, Valencia) and Italy (Marettimo, Sicily) were determined by GC/FID and GC/MS. The main constituents in most of the samples were aromatic monoterpenes corresponding to non-phenolic cyclic compounds (p-cymene, gamma-terpinene). The highest monoterpene concentrations were found in the Bosnian samples (70%), and the lowest in samples from the Balearic Islands ( 50%) in samples from Majorca with beta-bisabolene (>40%) being the principal constituent. Discriminant analysis (LDA) shows the differentiation of two chemotypes: A (phenol chemotype), with p-cymene and gamma-terpinene as characteristic compounds and B, with beta-bisabolene and carvacrol, as major and significative compounds. The occurrence of the chemotypes was related to summer positive precipitation and to deep of soils.Llorens, L.; Llorens Molina, JA.; Agnello, S.; Boira Tortajada, H. (2014). Geographical and environment-related variations of essential oils in isolated populations of Thymus richardii Pers. in the Mediterranean basin. Biochemical Systematics and Ecology. 56:246-254. doi:10.1016/j.bse.2014.05.0072462545

Proline as a biochemical marker in relation to the ecology of two halophytic Juncus species

"This is a pre-copyedited, author-produced PDF of an article accepted for publication in Journal of Plant Ecology following peer review."[EN] Aims Osmolytes, used for maintaining osmotic balance and as osmoprotectants , are synthesized in plants as a general, conserved response to abiotic stress, although their contribution to stress-tolerance mechanisms remains unclear. Proline, the most common osmolyte, accumulates in many plant species in parallel with increased external salinity and is considered a reliable biochemical marker of salt stress. We have measured proline levels in two halophytic, closely related Juncus species under laboratory and field conditions to assess the possible relevance of proline biosynthesis for salt tolerance and therefore for the ecology of these two taxa. Methods Proline was quantified in plants treated with increasing NaCl concentrations and in plants sampled in two salt marshes located in the provinces of Valencia and Alicante, respectively, in southeast Spain. Electrical conductivity, pH, Na+ and Cl− concentrations were measured in soil samples collected in parallel with the plant material. Important Findings Treatment with NaCl inhibited growth of J. acutus plants in a concentration-dependent manner, but only under high salt conditions for J. maritimus. Salt treatments led to proline accumulation in both species, especially in the more salt-tolerant J. maritimus. The results, obtained under laboratory conditions, were confirmed in plants sampled in the field. In all the samplings, proline contents were significantly lower in J. acutus than in the more tolerant J. maritimus growing in the same area. No direct correlation between soil salinity and proline levels could be established, but seasonal variations were detected, with increased proline contents under accentuated water deficit conditions. Our results suggest that proline biosynthesis is not only an induced, general response to salt stress but also an important contributing factor in the physiological mechanisms of salt tolerance in Juncus, and that it therefore correlates with the ecology of both species.Spanish Ministry of Science and Innovation and European Regional Development Fund to O.V. (CGL2008-00438/BOS); Polytechnic University of Valencia to M. B. (PAID-06-09).Boscaiu, M.; Lull, C.; Llinares Palacios, JV.; Vicente, O.; Boira Tortajada, H. (2013). Proline as a biochemical marker in relation to the ecology of two halophytic Juncus species. Journal of Plant Ecology. 6(2):177-186. https://doi.org/10.1093/jpe/rts017S1771866

Phytotoxic potential of Lantana camara, Eucalyptus camaldulensis, Eriocephalus africanus, Cistus ladanifer and Artemisia gallica aqueous extracts to control weeds

[EN] Weed management is necessary in natural and agricultural ecosystems. The most used control method in developed countries has been the application of chemical herbicides, which has caused many problems in human health and the environment as well as the development of resistant weeds due to the repeated use of herbicides with the same mode of action. Natural products could be an alternative to synthetic herbicides for weed management. The society is demanding new solutions and research of bioherbicides has increased in the last years. Aqueous extracts from some plant species contain allelopathic compounds that can inhibit the germination and the development and growth of other plants or organisms. In this work the phytotoxic potential of aqueous extracts from Mediterranean plants are studied in order to find new solutions for integrated weed management.Verdeguer Sancho, MM.; Blazquez, M.; Boira Tortajada, H. (2018). Phytotoxic potential of Lantana camara, Eucalyptus camaldulensis, Eriocephalus africanus, Cistus ladanifer and Artemisia gallica aqueous extracts to control weeds. Journal of Allelochemical Interactions. 4(2):17-26. http://hdl.handle.net/10251/121086S17264

Identification of Bioactive Compounds in Polar and Nonpolar Extracts of Araujia sericifera

Araujia sericifera is a native perennial, climbing laticiferous shrub from South America that is currently naturalized in many other countries. Previous data describe promising properties for A. sericifera, but no systematic study of its bioactive compounds and possible medicinal applications has been conducted to date. In the present study, aerial parts of A. sericifera (leaves, stems, and fruits) were explored by combining GC-MS and NMR spectroscopy analysis for both nonpolar (hexane) and polar (methanol) extracts. The hexanic extracts contained high amounts of pentacyclic triterpenes including two new metabolites, 3-tigloyl germanicol (18) and 3-tigloyl lupeol (19). The methanolic extracts revealed the presence of luteolin-7-glucoside (24), trigonelline (22), and conduritol F (23) as the main constituents. A multivariate study of a meaningful number of extracts allowed us to determine the distribution of compounds inside the plant. A cytotoxic evaluation in vitro showed that both leaf and fruit hexanic extracts presented a moderate activity against human breast carcinoma cell lines (MDA-MB-453 and MCF-7) and human colon carcinoma cell line (HCT-116) by the MTS [3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium] assay

Herbicidal Activity of Peumus boldus and Drimys winterii Essential Oils from Chile

[EN] The essential oil composition of Peumus boldus and Drimys winterii was analyzed by means of capillary GC-FID and GC-MS. More than 96% of the total oil components (43 and 54 compounds, respectively) were identified, with ascaridole (51.17 ± 9.51), p-cymene (16.31 ± 2.52) and 1,8-cineole (14.45 ± 2.99) as the main compounds in P. boldus and ¿-eudesmol (21.65 ± 0.41), followed of elemol (12.03 ± 0.34) and terpinen-4-ol (11.56 ± 1.06) in D. winterii. The herbicidal activity was tested against Amaranthus hybridus and Portulaca oleracea. P. boldus essential oil was the most phytotoxic against both weeds, inhibiting seed germination and seedling growth at all concentrations assayed (0.125-1 ¿L/mL). D. winterii essential oil did not show any effect on A. hybridus germination and only affected P. oleracea germination at the highest concentration. The results suggest the possible use of the essential oil from P. boldus as a natural herbicide. © 2010 by the authors.Research performed under an International Cooperation Project (number A/024753/09), financed by Agencia Espanola de Cooperacion Internacional para el Desarrollo (AECID).Verdeguer Sancho, MM.; García Rellán, D.; Boira Tortajada, H.; Pérez, E.; Gandolfo Wiederhold, SP.; Blazquez Ferrer, MA. (2011). Herbicidal Activity of Peumus boldus and Drimys winterii Essential Oils from Chile. Molecules. 16:403-411. doi:10.3390/molecules16010403S4034111

Effects of ion uptake for salt tolerance in several Mediterranean halophytes

The patterns of ion uptake were analysed in three dicotyledonous (Arthrocnemum macrostachyum, Sarcocornia fruticosa and Inula crithmoides) and two monocotyledonous (Juncus acutus and J. maritimus) halophytes, collected from a salt marsh in SE Spain. The experimental design included four plots in different positions within the marsh, and three sampling periods corresponding to spring, summer and autumn 2011. Electric conductivity, pH, and Na+, K+, Ca2+, Mg2+ and Cl- contents were determined in saturated soil extracts. In plants, the same ions were extracted in boiling water. In soil samples, spatial variation in the measured parameters among plots was higher than the seasonal variation within plots, whereas in plants significant differences in ion contents were detected only between species, but not between plots or sampling seasons for a given species. The dicot species under study are Na+ and Cl- accumulators, showing significant higher levels of these ions than the monocot taxa, but a direct correlation between ion content in soil and plants could be not establishedParra Boronat, L.; Llinares Palacios, JV.; Boscaiu Neagu, MT.; Donat-Torres, M.; Vicente Meana, Ó.; Boira Tortajada, H. (2013). Effects of ion uptake for salt tolerance in several Mediterranean halophytes. Bulletin of University of Agricultural Sciences and Veterinary Medicine Cluj-Napoca : Horticulture. 70(1):257-258. doi:10.15835/buasvmcn-hort:9504S25725870

Chemical composition and antifungal activity of Bubonium imbricatum volatile oil

The chemical composition of the essential oil extracted from the aerial parts of Bubonium imbricatum, an endemic plant of southern Morocco, was analysed. GC-MS showed 51 compounds, representing 60.2% of the total oil. Thymol isobutyrate (18.3%) and 2,5-dimethoxy-p-cymene (16.2%) were the major constituents of the oil. The oil was tested for antifungal activity in mycelial growth inhibition tests in vitro against three agricultural pathogenic fungi: Penicillium digitatum, P. expansum and Botrytis cinerea. The oil at 1000 ppm was highly effective against mycelial growth of P. digitatum with 99% inhibition. For P. expansum and B. cinerea the percentage of mycelial growth inhibition at 1000 ppm was respectively 87.2% and 87.8%. At 2000 ppm the oil was 100% effective in controlling mycelial growth of all three fungi. B. imbricatum essential oil was also tested at different concentrations on citrus fruits (Citrus reticulata Blanco cv. Nules) inoculated with P. digitatum (105 conidia ml-1). The oil had a fungistatic or fungicidal effect on C. reticulata

Influence of phenological barriers and habitat differentiation on the population genetic structure of the balearic endemic Rhamnus ludovici-salvatoris Chodat and R. alaternus L

[EN] Rhamnus ludovici-salvatoris, endemic to the Gymnesian Islands, coexists with the related and widespread R. alaternus in Mallorca and Menorca. In both species, the population genetic structure using RAPD, and flowering during a 3-year period to check for possible phenological barriers, were analyzed. Rhamnus ludovici-salvatoris showed lower genetic diversity and stronger population structure than R. alaternus, the Cabrera population being less diverse and the most differentiated. Rhamnus ludovici-salvatoris flowered one month later, although flowering of both species coincided sporadically. These congeners seem to have diverged through isolation by time and differentiation in habitat. The population genetic structure of R. ludovici-salvatoris could mainly be due to the existence of small populations on the one hand, and a gene flow caused by rare hybridization events on the other, which may also explain the presence of morphologically intermediate individuals in Menorca. The conservation of R. ludovici-salvatoris populations may include population reinforcements and other in situ interventions.Ferriol Molina, M.; Llorens García, L.; Gil, L.; Boira Tortajada, H. (2009). Influence of phenological barriers and habitat differentiation on the population genetic structure of the balearic endemic Rhamnus ludovici-salvatoris Chodat and R. alaternus L. Plant Systematics and Evolution. 277(1-2):105-116. doi:10.1007/s00606-008-0110-3S1051162771-2Affre L, Thompson JD, Debussche M (1997) Genetic structure of continental and island populations of the Mediterranean endemic Cyclamen balearicum (Primulaceae). Amer J Bot 84(4): 437–451BOIB (2005) Decreto 75/2005. BOIB 106: 29–32Bolmgren K, Oxelman B (2004) Generic limits in Rhamnus L. s.l. (Rhamnaceae) inferred from nuclear and chloroplast DNA sequence phylogenies. Taxon 53(2):383–390Bolòs O, Molinier R (1958) Recherches phytosociologiques dans l’île de Majorque. 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Edaphic characteristics of salt meadow vegetation in the eastern regions of Spain

Mediterranean halophytic rush vegetation was studied in the coastal marshes found in the Valencian region (Spain). Species achieving a frequency > 10% in vegetation relevés have been considered : Aeluropus littoralis , Artemisia caerulescens subsp. gallica , Arthrocnemum macrostachyum , Aster tripolium subsp. tripolium , Carex extensa , Centaurium spicatum, Inula crithmoides, Juncus acutus , Juncus maritimus , Juncus subulatus , Linum maritimum, Phragmites australis , Plantago crassifolia, Samolus valerandi , Schoenus nigricans, Scirpus maritimus var. compactus, Sonchus maritimus subsp. maritimus and Suaeda maritima. Four sociological groups were established by means of Principal Components Analysis (PCA) and their relationship to edaphic factors (water level, pH, total calcium carbonate, lime (active calcium carbonate), sulphates, organic matter, conductivity over saturation extract of the soil, salinity, Ca++, Mg++, Na+, Cl", S.A.R., total nitrogen and texture) were carried out using statistical analysis. Soil texture, total nitrogen and active calcium carbonate have a significant correlation on the distribution of this species. High lime content allows some glycophytes to support high concentrations of salt. Nomenclature follows Tutin, T.G. et al. (1964-1980).Les auteurs étudient la végétation halophile littorale (prés salés) des côtes de la région de Valence (Espagne) et son rapport avec les caractéristiques pédologiques . Pour l’analyse numérique ont été comprises les espèces présentes dans au moins 10% des relevés floristiques : Aeluropus littoralis, Artemisia caerulescens subsp. gallica, Arthrocnemum macrostachyum, Aster tripolium subsp. tripolium, Carex extensa, Centaurium spicatum, Inula crithmoides, Juncus acutus , Juncus maritimus, Juncus subulatus, Linum maritimum, Phragmites australis, Plantago crassifolia, Samolus valerandi, Schoenus nigricans, Scirpus maritimus var. compactus, Sonchus maritimus subsp. maritimus and Suaeda maritima. Quatre groupements ont été établis par l’analyse des composantes principales et son rapport avec les facteurs pédologiques déterminés (profondeur de la nappe, pH, carbonate de calcium, calcium active, sulfates, matière organique, conductivité électrique, salinité, Ca++, Mg , Na+, Cl- S.A.R., azote total et texture). Une corrélation significative existe entre les quatre groupes phytosociologiques et la texture, azote total et calcium actif. Par ailleurs, un taux élevé en calcium actif permet à quelques-uns des glycophytes de supporter des concentrations élevées de sel.Boira Herminio. Edaphic characteristics of salt meadow vegetation in the eastern regions of Spain. In: Ecologia mediterranea, tome 21 n°3-4, 1995. pp. 1-11