ent-Labdane glycosides from the aquatic plant Potamogeton lucens and analytical evaluation of the lipophilic extract constituents of various Potamogeton species

Two new ent-labdane glycosides, one known furano-ent-labdane and a new hydroxylated fatty acid were isolated from the dichloromethane extract of the freshwater aquatic plant Potamogeton lucens. The new compounds were assigned the structures of beta-d-glucopyranosyl-8(17),13-ent-labdadien-16,15-olid-18-oate, 18-beta-d-glucopyranosyloxy-8(17),13-ent-labdadien-16,15-olide and 13(R)-hydroxy-octadeca-(9Z,11E,15Z)-trien-oic acid by spectroscopic means. The algicidal activity of these compounds was tested against Raphidocelis subcapitata. Based on our previous study of Potamogeton pectinatus, other constituents were identified in P. lucens by LC-UV-MS, LC-NMR and GC-MS. The lipophilic extract profiles of both species are presented. Two other species, Potamogeton perfoliatus and P. crispus, were also investigated by analytical comparison of their non-polar extracts. The distribution of ent-labdanes characterized in Potamogeton is summarized.     

A closer look at the “Protopithecus” fossil assemblages: new genus and species from Bahia,Brazil

The recently extinct large-bodied New World monkey Protopithecus brasiliensis Lund 1836 was named based on a distal humerus and proximal femur found in the Lagoa Santa cave system in the southeastern Brazilian state of Minas Gerais. These bones are from an animal about twice the size of the largest extant platyrrhines. One hundred and seventy-five years later, a nearly complete skeleton was discovered in the Toca da Boa Vista caves in the neighboring state of Bahia and was allocated to the same taxon as it was the first platyrrhine fossil of comparable size found since the originals. Our detailed study of the equivalent elements, however, reveals important morphological differences that do not correspond to intraspecific variation as we know it in related platyrrhine taxa. The presence of both an expanded brachioradialis flange on the humerus and gluteal tuberosity on the femur of the Bahian skeleton distinguishes it from the Lagoa Santa fossil as well as from all other platyrrhines. Further cranial and postcranial evidence suggests a closer relationship of the former with the alouattine Alouatta, while the limited Lund material fits more comfortably with the ateline clade. Therefore, we propose to limit P. brasiliensis Lund to the distal humerus and proximal femur from Lagoa Santa and erect a new genus and species for the skeleton from Toca da Boa Vista. Cartelles coimbrafilhoi was a large-bodied frugivore with a relatively small brain and diverse locomotor repertoire including both suspension and climbing that expands the range of platyrrhine biodiversity beyond the dimensions of the living neotropical primates.     

Post-fire spread of alien plant species in a mixed broad-leaved forest of the Insubric region

How do tree species regenerate and which ecological conditions are required after forest fire in the Insubric region of the Alps? Are indigenous stand-forming tree species resistant over the invasion of alien plant species after such a disturbance? We addressed these questions in a case study in the Swiss canton of Ticino. In April 2006, a surface fire with severe intensity burnt a forest area of 55 ha on a south-facing slope (400-800 m.a.s.l.). The dominant trees in the investigated area were chestnut (Castanea sativa Mill.), beech (Fagus sylvatica L.) and deciduous oaks (Quercus spp.) mixed with tree species of intermediate height. Vegetation data were collected in May and August 2009 by systematic sampling. Resprouting of the survived trees and generative regeneration were analysed by counting vegetative shoots from sprouting stools, of seedling age, height and damage rate, respectively. Different vegetation structures related to low or high fire intensity were clearly visible three years after the forest fire, creating various habitats for both new invaders and seedlings of the stand-forming trees. The dominant chestnut was the only tree species that regenerated effectively by sprouting from stools. Seedlings of the stand-forming trees grew in high abundance under shadow conditions close to their mother trees which provided the seed source. In contrast, pioneer trees invaded patches where full light was available. Under such conditions the two main woody alien plant species, Ailanthus altissima and Robinia pseudoacacia, grew in high abundance. Due to the different ecological requirements of indigenous and alien tree seedlings, not any interaction between the two groups was detected.     

Flavonoids from the aquatic plant Eriocaulon buergerianum

Four flavonoids including (2S)-3',4'-methylenedioxy-5,7-dimethoxyflavan and hispidulin 7-(6-E-p-coumaroyl-beta-D-glucopyranoside), and one tocopherol were isolated from the capitulum of Eriocaulon buergerianum KOERN. Their structures were established by spectral and chemical evidence.     

Differential responses of the floating-leaved aquatic plant Nymphoides peltata to gradual versus rapid increases in water levels

We compared the growth responses of the floating-leaved species Nymphoides peltata to gradual and rapid rising water levels under two nutrient concentrations (1 g and 12 g of slow released fertilizer (N-P-K: 16-8-12) per container filled with 8 kg washed sand), and predicted the population expansion after these floods. The results showed that the capacity for petiole elongation was dependent on leaf age, and only leaves that were no more than five days old had the capability to reach the water surface when the water level increased rapidly from 50 cm to 300 cm. Plants subjected to a gradual rising water level tracked the increase in water depth whose petioles elongated at 3.96 ± 1.70 cm per day and 4.80 ± 0.16 cm per day under low and high nutrient concentrations respectively throughout the experiment period. When water levels were rapidly raised, leaf petioles elongated rapidly at 25.48 ± 1.51 cm per day and 26.64 ± 2.24 cm per day under low and high nutrient concentrations respectively during the first ten days. Plants under a constant water level maintained highest mean leaf recruitment (mean 3.0 ± 0.33 leaves and 24.4 ± 5.87 leaves every ten days under low and high nutrient concentrations, respectively). Therefore, more young leaves existed in the canopy ensuring that when the water level increases, young leaves can rapidly emerge after submergence. Gradual water level rise did not significantly affect biomass and ramet production (4.75 ± 1.41 g and 5.50 ± 1.22 ramets in low nutrient; 48.49 ± 21.45 g and 35.67 ± 11.78 ramets in high nutrient), but rapid water level rise negatively affected ramet production in both nutrient concentrations (3.00 ± 1.26 ramets and 11.25 ± 4.19 ramets in low and high nutrients, respectively). The results indicated that continual leaf recruitment and rapid petiole elongation were both important ways in which N. peltata adapted to increasing water levels. Extreme flooding may be a disturbance factor that affects plant growth and the population expansion of N. peltata, while small gradual water level rise should not harm this species.     

The “tomcat compound” 3-mercapto-3-methylbutanol occurs in the urine of free-ranging leopards but not in African lions or cheetahs

The felid-specific urinary odour compound 3-mercapto-3-methylbutanol and its precursors have been found in several felid species in captivity, but its presence in wild felids has not previously been investigated. We analysed the naturally deposited scent marks from three species of wild, free-ranging big cats in Northern Botswana and found 3-mercapto-3-methylbutanol in four samples of leopard urine (N = 13), but not in lion urine (N = 15) or cheetah urine (N = 6). Individual variation in the presence of the tomcat compound in samples from big cats in the wild may reconcile conflicting results from captive cats.     

The comparison of mechanically stimulated and spontaneous firings in traps of aquatic carnivorous Utricularia species

Firing and resetting of traps in aquatic Utricularia species are associated with water flows and trap volume changes. In this study, trap thickness was used as a measure of water flow and was monitored automatically using an electronic position sensor. Isolated traps from three aquatic Utricularia species were monitored over the course of 1-2 days to verify spontaneous firings (without any mechanical stimulation) and describe their basic characteristics. Isolated traps of three Utricularia species were initially fired by mechanical stimulation and allowed to naturally reset within a period of 24-48 h. Within this resting period, spontaneous firings were found in the traps of all species and in two trap age categories of U. vulgaris. The timing of spontaneous firings was found to be irregular. Spontaneous firings ranged between 0.29 and 2.4 during the 24-h resting period and the mean time between two spontaneous firings was highly variable within each species (319-891 min). There was no quantitative difference between spontaneous and mechanically stimulated firings of the traps. Spontaneous firings could explain how phytoplankton or detritus enters traps even when no prey species are present.     

云南会泽铅锌矿废弃矿渣堆常见植物内生真菌多样性

从云南会泽铅锌矿废弃矿渣堆上的常见植物硬毛南芥(Arabis hirsuta)、毛萼香茶菜(Rabbosia eriocalyx)和倒挂刺(Rosa longicuspis)等6种植物的690个组织块中共分离得到内生真菌495株,内生真菌的分离频率在0.42—0.93之间,平均为0.72,所有植物茎内生真菌的分离频率都明显高于叶(P<0.05)。经形态学鉴定,内生真菌分属于茎点霉属(Phoma)、交链孢属(Alternaria)和派伦霉属(Peyronellaea)等20个分类单元,其中茎点霉属和派伦霉属为该废弃矿渣堆上常见植物的优势内生真菌属。6种植物内生真菌的多样性指数在1.05—2.29之间,与其它非重金属污染环境植物内生真菌的多样性指数相似,说明在重金属污染地区仍然存在多种重金属耐受的内生真菌种类。6种植物内生真菌的相似性系数(0.455—0.833)表明,会泽铅锌矿区植物内生真菌的宿主专一性较小。     

Potential use in phytoremediation of three plant species growing on contaminated mine-tailing soils in Sardinia

We have analyzed the relationship between total Zn, Pb and Cu concentrations in the soil and the capacity of three plant species to accumulate these elements in their leaves. The study was carried out in a highly contaminated area at Sulcis-Iglesiente (SW-Sardinia, Italy). We took samples of the leaves of Dittrichia viscosa, Cistus salviifolius and Euphorbia pithyusa subsp. cupanii and samples of the soil beneath each of them at depths of 0-30 and 30-60 cm, both in contaminated mine tailings and surrounding areas. Due to the anthropic origin of the soil materials the results varied considerably. Bioavailability of trace elements was mainly related to the calcium-carbonate content and the crystalline and amorphous forms of iron in the soil. The concentration of Zn in the leaves of the three plant species studied was highest, followed by Pb and finally Cu. The leaves of Dittrichia viscosa contained the highest concentrations of trace elements and this species may be considered as being a “phytoextractor” in soils where the trace-element concentrations are not too high. Euphorbia pithyusa subsp. cupanii had low trace-element concentrations in its leaves despite growing in highly contaminated soils, and so might be used as a “phytostabilizer”. Although Cistus salviifolius does not grow in the most contaminated soils, could be considered as a contamination indicator up to a given level.     

Differences in penetration routes and establishment rates of four entomopathogenic nematode species into four white grub species

We compared the penetration of the entomopathogenic nematodes Steinernema scarabaei (AMK001 strain), S. glaseri (NC1 strain), Heterorhabditis zealandica (X1 strain), and H. bacteriophora (GPS11 strain) into third-instars of the scarabs Popillia japonica, Anomala orientalis, Cyclocephala borealis, and Rhizotrogus majalis. When larvae were exposed to nematodes for 6-72 h larval mortality and nematode establishment rate and occasionally speed of kill often showed the same pattern within nematode-white grub combinations. But no two nematodes or white grub species had the same pattern for these observations for all white grub or nematode species, respectively. Mortality, establishment, and speed of kill followed a similar pattern for H. zealandica, S. glaseri, and S. scarabaei, but there was no clear relationship for H. bacteriophora. Significant nematode establishment was only observed after at least 48 h exposure in most nematode-white grub combinations. Faster establishment was observed only for H. zealandica in A. orientalis and R. majalis (after 24 h) and for S. scarabaei in P. japonica and R. majalis (after 12 h). Nematode establishment after 72 h in the different scarab species was generally low for S. glaseri (<1.5%) and H. bacteriophora (<3%), higher for H. zealandica (2-5%), and the highest for S. scarabaei (1-14%). However, in another experiment establishment was generally higher after 96h exposure. Nematode penetration sites were determined by comparing nematode establishment in larvae with mouth, anus, mouth+anus, or none sealed with glue. The trends for each nematode species were very similar in the different white grub species. H. zealandica and H. bacteriophora showed excellent cuticular penetration ability but may also penetrate through mouth and/or anus. S. glaseri also penetrated through the cuticle but lower establishment in larvae with mouth or mouth+anus sealed suggested that the mouth is an important penetration site. S. scarabaei showed a preference for the mouth as a penetration site, but it showed some cuticular penetration ability and may also use the anus as a penetration site. The methodology used cannot exclude that cuticular penetration also included penetration through the spiracles. To fully understand the effect of nematode and white grub species on nematode virulence, future studies will have to compare host immune response to the penetrating IJs and the role of the symbiotic bacteria in these interactions.     

Inherited maternal effects on the drought tolerance of a natural hybrid aquatic plant, <Emphasis Type="Italic">Potamogeton anguillanus</Emphasis>

We tested whether maternal effects have led to the adaptive divergence of strains of the natural hybrid Potamogeton anguillanus, whose putative parents show contrastingly divergent ecologies. To examine the correlation between phenotypic characters and maternal types, we conducted drought experiments and DNA typing using nuclear and chloroplast genes. In the field, we investigated the distribution of the maternal type along the depth and the inshore-offshore gradient. Hybrids of P. malaianus mothers (M-hybrids) and those of P. perfoliatus mothers (P-hybrids) could not be distinguished morphologically under submerged conditions, but differed in drought tolerance. M-hybrids and P. malaianus formed more terrestrial shoots and exhibited higher survival than P-hybrids and P. perfoliatus in drought experiments. The distribution survey clarified that M-hybrids were dominant in shallow and inshore areas, whereas they were almost absent in deeper and offshore areas. These results indicate that the natural hybrid P. anguillanus differs in adaptive values depending on the maternal type. Bidirectional hybridization and heritable maternal effects may have played important roles in its phenotypic adaptation to local environmental conditions. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Antioxidant dehydrotocopherols as a new chemical character of Stemona species

From the roots of various Stemona species four new dehydrotocopherols (chromenols) were isolated and their structures and stereochemistry elucidated by spectroscopic methods. The double bond between C-3 and C-4 proved to be a typical chemical character of the genus found in most of the species. Various C-methylations of the aromatic ring reflect differences in methyltransferase activities and agreed with the current species delimitations showing an exclusive accumulation of dehydro-delta-tocopherol for the Stemona tuberosa group, whereas different provenances of Stemona curtisii were characterized by dehydro-gamma-tocopherol accompanied by small amounts of dehydro-alpha-tocopherol. From Stemona collinsae all four tocopherols were isolated with a clear preponderance of dehydro-delta-tocopherol accompanied by smaller amounts of the rare dehydro-beta-tocopherol. Stemona burkillii and a group of unidentified species showed a weak accumulation trend towards dehydro-alpha-tocopherol, whereas Stemona cochinchinensis and especially Stemona kerrii clearly differed by a preponderance of chromanol derivatives. In Stemona cf. pierrei no tocopherols could be detected at all. Based on TLC tests and microplate assays with the free radical 2,2-diphenyl-1-picrylhydrazyl (DPPH*) the antioxidant capacities of all chromenol derivatives were comparable with that of alpha-tocopherol showing no significant differences among each other, except for a more rapid kinetic behaviour of the 5,7,8-methylated dehydro-alpha-tocopherol.     

Evidence of formation of glushinskite as a biomineral in a Cactaceae species

The X-ray diffractometric and infrared spectroscopic investigation of crystalline material isolated from the Cactaceae species Opuntia ellisiana shows the presence of a very complex mineral composition, including whewellite (monohydrated calcium oxalate), opal (SiO2), calcite (CaCO3) and glushinskite (dihydrated magnesium oxalate). This is the first report of the presence of magnesium oxalate in plants.     

Identification of unusual fatty acids of four alpine plant species from the Pamirs

Fatty acid composition and structure in total lipids from the green above-ground parts of four alpine plants, Oxygraphis glacialis, Primula macrophylla, Rhodiola pamiroalaica, and Swertia marginata, were established by GC and GC-MS. A total of 55 fatty acids was detected, and 48 of them were identified. Ubiquitous palmitate, linoleate, and linolenate predominated in the lipids accounting for about 72-90% of the total fatty acids. At the same time, the latter contained numerous species, which were unusual for higher plants and included saturated odd-numbered n-acids (six C15-C25 species, 0.26-1.40%), saturated even-numbered very-long-chain n-acids (six C20-C30 species, 1.00-2.49%), iso-acids (nine C15-C26 species, 0.64-1.53%), anteiso-acids (four C15-C20 species, 0.08-1.57%), certain uncommon mono- and dienoic acids, as well as 16:3omega3, 18:3omega6, and 18:4omega3 acids that are absent from the most higher plants. Nine fatty acids were found here for the first time in higher plants and two may be new to science. The evidence on the unusual fatty acids is discussed with respect to their distribution in living organisms, pathways of biosynthesis, and chemotaxonomic role.     

Bicarbonate use in three aquatic plants

Our study aimed to test the ability of aquatic plants to use bicarbonate when acclimated to three different bicarbonate concentrations. To this end, we performed experiments with the three species Ceratophyllum demersum, Egeria densa, Lagarosiphon major to determine photosynthetic rates under varying bicarbonate concentrations. We measured bicarbonate use efficiency, photosynthetic performance and respiration. For all species, our results revealed that photosynthetic rates were highest in replicates grown at low alkalinity. Thus, E. densa had approx. five times higher rates at low (264 ± 15 μmol O₂ g⁻¹ DW h⁻¹) than at high alkalinity (50 ± 27 μmol O₂ g⁻¹ DW h⁻¹), C. demersum had three times higher rates (336 ± 95 and 120 ± 31 μmol O₂ g⁻¹ DW h⁻¹), and L. major doubled its rates at low alkalinity (634 ± 114 and 322 ± 119 μmol O₂ g⁻¹ DW h⁻¹). Similar results were obtained for bicarbonate use efficiency by E. densa (136 ± 44 and 43 ± 10 μmol O₂ mequiv. L⁻¹ g⁻¹ DW h⁻¹) and L. major (244 ± 29 and 82 ± 24 μmol O₂ mequiv. L⁻¹ g⁻¹ DW h⁻¹). As to C. demersum, efficiency was high but unaffected by alkalinity, indicating high adaptation ability to varied alkalinities. A pH drift experiment supported these results. Overall, our results suggest that the three globally widespread worldwide species of our study adapt to low inorganic carbon availability by increasing their efficiency of bicarbonate use.     

Black yeast habitat choices and species spectrum on high altitude creosote-treated railway ties

Polyextremotolerant black yeast-like fungi thrive in moderately hostile environments where they are concomitantly subjected to several types of stress, such as toxicity, scarce nutrient availability, and high or low temperature extremes. Their ability to assimilate alkylbenzenes (toxic environmental pollutants) enhances their growth in harsh conditions, including on railway ties. Samples were collected using cotton swabs, premoistened with physiological saline, from 658 oak and concrete railway ties at six train stations in Turkey at altitudes ranging between 1026 and 1427 m. The samples were inoculated on malt extract agar supplemented with chloramphenicol, and incubated at 26 °C for 4 weeks. Twenty-four samples (3.6 %), 17 from oak and 7 from concrete (5.6 % vs. 2 %; P = 0.02), tested positive for fungi. Exophiala crusticola was found to be the most common species (n = 13), followed by Exophiala phaeomuriformis (n = 7) and Exophiala heteromorpha (n = 4). These results suggest that hydrocarbons, particularly creosote-treated oak woods, support the growth of black yeasts, some of which are opportunists in humans.     

Phylogenetic characterisation of Taenia tapeworms in spotted hyenas and reconsideration of the “Out of Africa” hypothesis of Taenia in humans

The African origin of hominins suggests that Taenia spp. in African carnivores are evolutionarily related to the human-infecting tapeworms Taenia solium, Taenia saginata and Taenia asiatica. Nevertheless, the hypothesis has not been verified through molecular phylogenetics of Taenia. This study aimed to perform phylogenetic comparisons between Taenia spp. from African hyenas and the congeneric human parasites. During 2010–2013, 233 adult specimens of Taenia spp. were collected from 11 spotted hyenas in Ethiopia. A screening based on short DNA sequences of the cytochrome c oxidase subunit 1 gene classified the samples into four mitochondrial lineages designated as I–IV. DNA profiles of nuclear genes for DNA polymerase delta (pold) and phosphoenolpyruvate carboxykinase (pepck) showed that lineages II and III can be assigned as two independent species. Common haplotypes of pold and pepck were frequently found in lineages I and IV, suggesting that they constitute a single species. Morphological observations suggested that lineage II is Taenia crocutae, but the other lineages were morphologically inconsistent with known species, suggesting the involvement of two new species. A phylogenetic tree of Taenia spp. was reconstructed by the maximum likelihood method using all protein-coding genes of their mitochondrial genomes. The tree clearly demonstrated that T. crocutae is sister to T. saginata and T. asiatica, whereas T. solium was confirmed to be sister to the brown bear tapeworm, Taenia arctos. The tree also suggested that T. solium and T. arctos are related to two species of Taenia in hyenas, corresponding to lineages I + IV and III. These results may partially support the African origin of human-infecting Taenia spp., but there remains a possibility that host switching of Taenia to hominins was not confined to Africa. Additional taxa from African carnivores are needed for further testing of the “Out of Africa” hypothesis of Taenia in humans.     

Decomposition of four macrophytes in wetland sediments: Organic matter and nutrient decay and associated benthic processes

Decomposition rates of Phragmites australis, Carex riparia, Nuphar luteum and Salvinia natans and benthic processes were measured from December 2003 to December 2004 in a shallow wetland (Paludi di Ostiglia, Northern Italy) by means of litter bags and intact cores incubations. Decay rate was highest for N. luteum (k = 0.0152 d⁻¹), intermediate for S. natans (k = 0.0041 d⁻¹) and similar for P. australis (k = 0.0027 d⁻¹) and C. riparia (k = 0.0028 d⁻¹).Benthic metabolism followed a seasonal pattern with summer peaks of O₂ demand and TCO₂, CH₄ and NH₄⁺ efflux whilst soluble reactive phosphorus (SRP) fluxes were negligible also under hypoxic conditions, indicating that P was mainly retained by sediment. The initial C:P ratio was similar in N. luteum and S. natans (170) and significantly lower than that of P. australis and C. riparia (360). During the detritus decay P was progressively lost by N. luteum and S. natans tissues, whereas, after an initial leaching, it was probably re-used during the microbial decomposition of the more refractory P. australis and C. riparia detritus. Nuphar luteum, P. australis and S. natans had comparable initial C:N mass ratio (15), significantly lower than that of C. riparia (26). The C:N ratio was rather constant for N. luteum (12.9 ± 1.5) and S. natans (14.6 ± 0.9), decreased slightly to below 20 for C. riparia and increased up to 30 for P. australis. Overall, differences among species were likely due to the recalcitrance of decomposing detritus, whilst process rates were controlled by limitation of microbial processes by nutrients and electron acceptor availability.     

Condition dependence of iridescent wing flash-marks in two species of dabbling ducks

Growing empirical evidence supports the hypothesis of male mate choice for female ornaments which are thought to reflect individual quality and future breeding ability. While structural colors are clearly used in mate choice and pairing, the condition dependence of such traits is less obvious, particularly in females. We present spectral measurements of wing flash-marks in two species of dabbling ducks during the pairing period and evaluate color and brightness contrasts as seen through the mallard's (Anas platyrhynchos) visual system. We tested for possible relationships between body size (and condition) and feather measurements both on captive and wild individuals. By analyzing reflectance spectra of semi-captive mallards soon after the molting period, we found that brightness was condition related. Color contrast was positively related to body size, but only in females. In wild ducks, color contrast was positively related to body size in the common teal A. crecca only for females. These results suggest that female color traits are likely to be used by males for mate choice, and support the hypothesis that the structural color is condition-dependent. Finally, brightness contrast decreased over time in both duck species. Natural abrasion or the effect of keratinolytic bacteria could explain such pattern.