The evolution of the ribosomal loci in the subgenusLeopoldia of the genusMuscari (Hyacinthaceae)

In the subgenusLeopoldia of the genusMuscari, M. comosum is an exceptional species because it presents the most asymmetrical karyotype of the group and because its only active NOR is located in the fifth chromosome pair, while in the other species it is located in the first or second chromosome pairs (all the species have 2n = 18 chromosomes). SinceM. comosum has a derived karyotype different from those of the other species of the group, the resulting question is whether, in the first and second chromosome pair of this species, ribosomal cistrons persist. Observations after fluorescence in situ hybridization (FISH) using rDNA probes indicate that there are indeed ribosomal loci in the first and second chromosome pairs of this species, although these loci are inactive with respect to nucleolus organization. The location of rDNA regions in another three species of the same genus (M. atlanticum, M. dionysicum andM. matritensis) provides a basis for examining the significance of these findings in relation to the evolution of the ribosomal loci in this genus. Our observations indicate that in the genusMuscari, the largest sites for rRNA genes are not necessarily active, and, therefore, the activation of these regions is not related to the number of copies but to a specific regulation mechanism.     

柠檬酸和EDTA对铜污染土壤环境中吊兰生长的影响

通过盆栽试验研究了在铜污染条件下,柠檬酸和EDTA作为活化剂对铜污染土壤中吊兰生长状况的影响.结果表明,柠檬酸和EDTA对吊兰富集量的影响与其对土壤中铜的活化能力呈显著性正相关.柠檬酸对土壤铜有较强的活化作用,能够有效提高吊兰对铜的吸收,且在浓度为5mmol/L时效果最为明显,而较高的铜富集量又抑制了吊兰的生长;EDTA对吊兰富集能力的影响相对较弱,对吊兰的生长也无显著影响.相比而言,柠檬酸对铜污染土壤中吊兰生长状况的影响比EDTA大.     

Comparative phenological and water potential patterns of three Calligonum species in the eastern great Erg of Tunisia

Calligonum azel, C. comosum and C. arich (Polygonaceae) are three dominant and economically important species widely distributed in active sand dunes in the southern desert of Tunisia, which differ in growth form and may co-occur under the same climatic constraints. The aims of this work were to compare their phenological and water potential patterns, as well as branch, flower and fruit production during three years at monthly intervals. Predawn (Ψ_pd) and midday (Ψ_md) water potentials followed similar trends with a few exceptions. For all species, Ψ_md reached values more negative than −2.5 MPa during the hot and dry summer, with extremes in July. Ψ_pd differed between the species, and C. comosum attained the most negative values (−1.71 MPa). Seasonal differences in Ψ_pd were less pronounced for Calligonum species established in dunes as compared to C. comosum from interdunes. Spatial and temporal variations in soil water content provoked changes in water potentials of these species. Diurnal amplitudes resulting from the difference between Ψ_md and Ψ_pd were more pronounced during the dry season compared to the wet months. The phenological pattern of the three species showed a similar sequence of phenophases with growth activity occurring mostly between spring and summer. We found a species-dependent response to summer drought, as C. comosum ended all phenophases in June, while C. azel and C. arich extended their vegetative growth into the summer period of low precipitation. Water availability for the plants was better on the dune slopes. Differences were statistically significant among species, concerning green branch production and numbers of initially formed flowers and mature fruits. Our data suggest that changes in the studied parameters may depend on the rooting depth of the species.     

Facilitative interactions do not wane with warming at high elevations in the Andes

Positive interactions between species are known to play an important role in the structure and dynamics of alpine plant communities. The balance between negative and positive interactions is known to shift along spatial and temporal gradients, with positive effects prevailing over negative ones as the environmental stress increases. Thus, this balance is likely to be affected by climate change. We hypothesized that increases in temperature (a global warming scenario) should decrease the importance of positive interactions for the survival and growth of alpine plant species. To test this hypothesis, we selected individuals of the native grass species Hordeum comosum growing within the nurse cushion species Azorella madreporica at 3,600 m.a.s.l. in Los Andes (Chile), and performed nurse removal and seedling survival experiments under natural and warmer conditions. For warmer conditions, we used open-top chambers, which increased the temperature by 4 °C. After two growing seasons, we compared the effect of nurse removal on the survival, biomass, and photochemical efficiency of H. comosum individuals under warmer and natural conditions. Nurse removal significantly decreased the survival, biomass, and photochemical efficiency of H. comosum, demonstrating the facilitative effects of nurse cushions. Seedling survival was also enhanced by cushions, even under warmer conditions. However, warmer conditions only partially mitigated the negative effects of nurse removal, suggesting that facilitative effects of cushions do not wane under warmer conditions. Thus, facilitative interactions are vital to the performance and survival of alpine species, and these positive interactions will continue to be important in the warmer conditions of the future in high-alpine habitats.     

Nucleotide diversity of the homoeologous adh1 loci in the American allotetraploid Oryza species

On Kilimanjaro, Tanzania two rather different forms of Chlorophytum comosum were observed. One form occurred on higher altitudes, the other on lower altitudes. Morphological, molecular and ecological studies conclude that the two forms both are entitled to species recognition. The high altitude form must still be referred to C. comosum s.l., while the low altitude form is a new species and it is described as C. rhizopendulum Bjorå & Hemp sp. nov. The two species inhabit mutually completely exclusive habitats on Kilimanjaro. Whereas C. comosum has a wide ecological potential, C. rhizopendulum has narrow ecological demands as a highly adapted specialist. The two species are easily distinguished morphologically. Molecular studies show that C. comosum is of polyphyletic origin, and the species complex needs revision.     

Phenoloxidase-producing halotolerant fungi from olive brine wastewater

The main aim of this study was to assess the ability of producing extracellular phenoloxidases (EPO) of fungi isolated from olive brine wastewater (OBW), the effluent from the debittering process of table olives. Five out of twenty isolates displayed EPO-producing ability as assessed by selective agar plate assays and were all halotolerant. Among them, Citeromyces matritensis (syn. Candida globosa) and Aspergillus fumigatus concomitantly produced laccase and Mn-peroxidase (MnP) activities. Candida boidinii and Candida bombi, instead, only produced laccase and Candida diddensiae only released MnP. Both C. matritensis and A. fumigatus, grown in shaken cultures on OBW, maintained their EPO-producing ability and removed phenols by 52.3 and 82.3%, respectively, after 10 d incubation in the non-supplemented effluent. These results might suggest the possible use of these strains in the treatment of other saline phenol-rich effluents, such as pickling and tannery wastewater.     

22种木莲属植物亲缘关系的ISSR分析

利用ISSR标记分析技术探讨了22种木莲属植物的遗传亲缘关系。选用10对ISSR引物组合对木莲属22个种的基因组进行分析。结果表明：22个种共扩增出595条DNA带,其中多态性条带占94.45%;根据Nei Li遗传相似性系数在0.68处,UPGMA聚类结果将22个种划分为6个类群,在0.70处进一步可分为12个亚类群;22种木莲属植物的Nei-Li遗传相似性系数变化范围为0.605(乳源木莲与球果木莲之间)～0.956(中缅木莲与滇南木莲之间),平均遗传相似性系数为0.698。说明木莲属植物种间差异性大。其中中缅木莲、滇南木莲之间遗传相似性系数为0.956,两者亲缘关系最近。该结果同时支持将巴东木莲、乳源木莲、滇桂木莲分别作为独立的种。     

DNA barcoding of selected UAE medicinal plant species: a comparative assessment of herbarium and fresh samples

It is commonly difficult to extract and amplify DNA from herbarium samples as they are old and preserved using different compounds. In addition, such samples are subjected to the accumulation of intrinsically produced plant substances over long periods (up to hundreds of years). DNA extraction from desert flora may pause added difficulties as many contain high levels of secondary metabolites. Herbarium samples from the Biology Department (UAE University) plant collection and fresh plant samples, collected from around Al-Ain (UAE), were used in this study. The three barcode loci for the coding genes matK, rbcL and rpoC1-were amplified. Our results showed that T. terresteris, H. robustum,T. pentandrus and Z. qatarense were amplified using all three primers for both fresh and herbaium samples. Both fresh and herbarium samples of C. comosum, however, were not amplified at all, using the three primers. Herbarium samples from A. javanica, C. imbricatum, T. aucherana and Z. simplex were not amplified with any of the three primers. For fresh samples 90, 90 and 80% of the samples were amplified using matK, rbcL and rpoC1, respectively. In short, fresh samples were significantly better amplified than those from herbarium sources, using the three primers. Both fresh and herbarium samples from one species (C. comosum), however, were not successfully amplified. It is also concluded that the rbcL regions showed real potentials to distinguish the UAE species under investigation into the appropriate family and genus.     

Three 3-benzyl-4-chromanones from Muscari comosum

Three novel 3-benzyl-4-chromanones have been isolated from the bulbs of Muscari comosum.     

Screening of potential cytotoxic activities of some medicinal plants of Saudi Arabia

Phytochemicals from plant extracts belong to an important source of natural products which have demonstrated excellent cytotoxic activities. However, plants of different origins exhibit diverse chemical composition and bioactivities. Therefore, discovery of plants based new anticancer agents from different parts of the world is always challenging. In this study, methanolic extracts of different parts of 11 plants from Saudi Arabia have been tested in vitro for their anticancer potential on human liver cancer cell line (HepG2). Particularly, for this study, plants from Asteraceae, Resedaceae and Polygonaceae families were chosen on the basis of locally available ethnobotanical data and their medicinal properties. Among 12 tested extract samples, three samples obtained from Artemisia monosperma stem, Ochradenus baccatus aerial parts and Pulicaria glutinosa stem have demonstrated interesting cytotoxic activities with a cell viability of 29.3%, 28.4% and 24.2%, respectively. Whereas, four plant extracts including Calendula arvensis aerial parts, Scorzonera musilii whole plant, A. monosperma leaves show moderate anticancer properties bearing a cell viability ranging from 11.9 to 16.7%. The remaining extracts have shown poor cytotoxic activities. Subsequently, GC-MS analysis of methanolic extracts of four most active plants extracts such as C. comosum, O. baccatus, P. glutinosa and A. monosperma detected the presence of 41 phytomolecules. Among which 3-(4-hydroxyphenyl) propionitrile (1), 8,11-octadecadiynoic acid methyl ester (2), 6,7-dimethoxycoumarin (3) and 1-(2-hydroxyphenyl) ethenone (4) were found to be the lead compounds of C. comosum, O. baccatus P. glutinosa and A. monosperma, respectively.     

Homoisoflavanones from Muscari comosum bulbs

From the bulbs of Muscari comosum 3,9-dihydropunctatin and three novel homoisoflavanones were isolated.     

Fluorescence Properties of Guard Cell Chloroplasts: EVIDENCE FOR LINEAR ELECTRON TRANSPORT AND LIGHT-HARVESTING PIGMENTS OF PHOTOSYSTEMS I AND II

The presence of chloroplasts in guard cells from leaf epidermis, coleoptile, flowers, and albino portions of variegated leaves was established by incident fluorescence microscopy, thus confirming the notion that guard cell chloroplasts are remarkably conserved. Room temperature emission spectra from a few chloroplasts in a single guard cell of Vicia faba showed one major peak at around 683 nanometers. Low-temperature (77 K) emission spectra from peels of albino portions of Chlorophytum comosum leaves and from mesophyll chloroplasts of green parts of the same leaves showed major peaks at around 687 and 733 nanometers, peaks usually attributed to photosystem II and photosystem I pigment systems, respectively. Spectra of peels of V. faba leaves showed similar peaks. However, fluorescence microscopy revealed that the Vicia peels, as well as those from Allium cepa and Tulipa sp., were contaminated with non-guard cell chloroplasts which were practically undetectable under bright field illumination. These observations pose restrictions on the use of epidermal peels as a source of isolated guard cell chloroplasts. Studies on the 3-(3,4-dichlorophenyl)-1,1-dimethylurea-sensitive variable fluorescence kinetics of uncontaminated epidermal peels of C. comosum indicated that guard cell chloroplasts operate a normal, photosystem II-dependent, linear electron transport. The above properties in combination with their reported inability to fix CO₂ photosynthetically may render the guard cell chloroplasts optimally suited to supply the reducing and high-energy phosphate equivalents needed to sustain active ion transport during stomatal opening in daylight.     

3-Benzyl-4-chromanones from Muscari comosum

From the bulbs of Muscari comosum two novel 3-benzyl-4-chromanones, 7-O-methyl-3,9-dihydropunctatin and 8-O-demethyl-7-O-methyl-3,9-didropunctatin, were isolated.     

Seed-propagated Muscari comosum (L.) Mill.: Effects of sowing date and growing conditions

Muscari comosum is a widespread Mediterranean species with a long use as food. The edible part is the bitter bulb that has to be cooked. The increasing value of bulbs, also due to a renewed cultural interest toward traditional foods and their benefits for health, claims to enhance the agricultural production. Surprisingly, no agronomic studies about the best practice of propagation exist. We tested whether and how germination rate and weight and size of bulbs, after one growing season, were affected by sowing date (autumn–spring), growing condition (greenhouse, shaded greenhouse and open field), and container’s volume. Results showed that the best-sowing period ranges between September and January; following this period there is a huge decrease in germination rate. The time of seedling emergence was higher in open field than in protected environment. The longer interval of growing was observed with the sowing of October that produced heavier and larger bulbs. The best combination to obtain larger bulbs is sowing in October under greenhouse. However, under shaded conditions it was possible to obtain satisfactory results even with medium-late sowing (December and January). Containers with higher volume generally performed better. We conclude that mass propagation of M. comosum could be efficiently performed for agronomic purposes using nurseries. In fact, due to the high rate of germination and to the ease of obtaining the seeds from wild populations or from cultivations, there is the possibility to produce large quantities of bulbs to develop new crops of this traditional food.     

Late Turolian Mesopithecus (Mammalia: Cercopithecidae) from Axios Valley (Macedonia,Greece): earliest presence of M. monspessulanus in Europe

The fossil mammal localities of the Axios Valley (Macedonia, Greece) yielded a rich collection of Mesopithecus remains, which were first described at the beginning of the 1990s. The late Turolian Dytiko localities include several specimens of Mesopithecus, which were originally separated in two size-related forms: the relatively larger-sized M. cf. or aff. pentelicus, and the relatively smaller-sized M. cf. monspessulanus. However, some Dytiko specimens were only partially described, or remained even undescribed because the cranium either was still in connection with the mandible or was markedly deformed. Later, careful cleaning of the materials and their revision based on larger comparative samples indicate that they represent two distinct species: the relatively larger-sized specimens belong to M. pentelicus, while the relatively smaller-sized ones to M. monspessulanus. The Dytiko M. pentelicus has slightly smaller dental dimensions compared to M. pentelicus from Pikermi, indicating a possible trend for size decrease. The Dytiko M. monspessulanus, although close to the typical form of this species, has somewhat larger dimensions. The semi-terrestrial M. pentelicus disappeared at the end of the Miocene, while some of its populations adapted to the wetter and more woody Pliocene habitats, finally giving origin to M. monspessulanus, whose elbow-joint indicates an arboreal lifestyle. M. monspessulanus was widely distributed in Europe, but its remains are very scarce and are all from the Pliocene. Some questionable indications for the presence of M. monspessulanus in the latest Miocene come from some Italian Messinian sites (Gravitelli, Baccinello V3), but this scenario still needs verification. However, even if its presence in some Italian localities was confirmed, the Dytiko M. monspessulanus nonetheless represents the earliest known occurrence of this species in Europe, as the Dytiko fauna is considered as latest Turolian (pre-Messinian, 7.0–6.0 Ma).     

First record of insect pollinators visiting Muscari comosum (L.) Miller (Liliaceae-Hyacinthaceae), an ancient Mediterranean food plant

Insects foraging on Muscari comosum flowers belong to 3 families, 10 genera and 13 species. The most abundant species was the hairy-footed flower bee, Anthophora plumipes. All species, except two cleptoparasites, presented pollen on their bodies. Muscari comosum flowering in early spring can be a key food source for pollinators.     

Free space iron pools in roots: generation and mobilization

A rapid and simple method for the determination of a ferric iron pool in the free space of roots is described. Formation of this pool depended on the source of iron in the nutrient solution. During growth in water culture at pH 5 to 6 with Fe-ethylenediaminetetraacetate, a free space pool of 500 to 1000 nanomoles Fe per gram fresh weight was formed in the roots of bean (Phaseolus vulgaris L. var. Prélude), maize (Zea mays L. var. Capella), and chlorophytum (Chlorophytum comosum [Thunb.] Jacques). No significant pool (less than 100 nanomoles per gram fresh weight) was formed with ferrioxamine. Upon impending Fe deficiency, bean and chlorophytum were able to mobilize this pool. Fe-deficient bean plants mobilized iron from the free space iron pool of another plant in the same vessel.     

Phenolic diterpenoids of some Podocarps

The woods of 10 species of the Podocarpaceae have variously yielded 12 phenolic diterpenoids. These include the Fijian members Dacrydium nidulum, Decussocarpus vitiensis, Podocarpus neriifolius and Dacrycarpus imbricatus, as well as Podocarpus gracilior, P. polystachus, P. sylvestris, P. gnidioides, Dacrydium comosum and D. falciforme.     

Trace elements (Al,Cd, Cr,Cu, Fe,Mn, Ni,Pb and Zn) in Mytilus galloprovincialis and Tapes decussatus from Faro and Ganzirri Lakes (Sicily,Italy): Flow cytometry applied for hemocytes analysis

BackgroundTrace elements present in sessile molluscs, are important because they are used in human consumption and it has significantly increased in recent years. While their filtering of the water can lead to their build-up of organic and inorganic materials that can be sampled and analyzed, this can also lead to bioaccumulation of harmful substances, such as essential and non-essential elements, that can harm the human health if in taken in high concentrations or for a long period of time.MethodsIn the present study, the trace metal content (Al, Cd, Cr, Cu, Fe, Mn, Ni, Pb and Zn) of two sessile crustaceans, 20 Mytilus galloprovincialis (mussel) and 20 Tapes decussatus (clam) in Faro and Ganzirri Lakes (Messina, Sicily, Italy) were analyzed. Haemolymph samples were taken on both molluscs in order to analyze the haemocyte population by flow cytometric analysis. Unpaired t-tests were used to determine significant differences for the essential and non-essential metallic elements concentrations in the lake waters and in the tissues of M. galloprovincialis and T. decussatus and for hemocyte populations R1 (halinocytes) and R2 (granulocytes).ResultsThe results suggested that that in Faro Lake, the tissue Al, Cr and Pb levels in M. galloprovincialis were higher than those for T. decussatus, in contrast to Mn, Fe, Ni, Cu, Zn and Cd, which were higher in T. decussatus. Unpaired t-tests showed that there were significantly higher proportions of halinocytes in M. galloprovincialis versus T. decussatus for both Faro Lake (41.8 % vs. 24.3 %; P < 0.001) and Ganzirri Lake (43.0 % vs. 22.4 %; P < 0.001). In contrast, while there were significantly higher proportions of granulocytes in Faro Lake (21.2 % vs. 9.1 %; P < 0.001), this difference was not seen for the granulocytes of M. galloprovincialis versus T. decussatus in Ganzirri Lake (9.6 % vs. 13.0 %).ConclusionThis study shows that M. galloprovincialis and T. decussatus can indeed bioaccumulate some of these metal, such that activation of the immune responses is specific to certain cell types. Future research must focus on the balance of trace elements in the consumption of these shellfish, and analyzes with more sophisticated tools can be used to diagnose the increased concentration of trace elements and the quantification of trace metals from shellfish to clams.     

An almost complete skeleton of Metailurus parvulus (Carnivora, Felidae) from the late Miocene of Kerassia (Northern Euboea, Greece)

We describe a partial skeleton of Metailurus parvulus from the Turolian site of Kerassia 1 (Northern Euboea, Greece). The material, which consists of a mandible, the anterior and posterior limb-bone elements, some sternal bones and some vertebrae, is the most complete known of this species. The dental material is compared to specimens from Pikermi and Chomateri (Greece), and China. The limb-bones available offer us the possibility to discuss the status of some previously described specimens from Pikermi. The limb proportions indicate that M. parvulus had elongated posterior limbs relative to the anterior ones, which reflects developed jumping skills. M. parvulus had moderately developed cursorial abilities, intermediate between open and closed habitat felids, and probably frequented primarily relatively open woodlands.