Plant Biosystems

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Online ISSN: 1126-3504
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Article
Ecological research on extreme environments can be applied to exobiological problems such as the question of life on Mars. If life forms (fossil or extant) are found on Mars, their study will help to solve fundamental questions about the nature of life on Earth. Extreme environments that are beyond the range of adaptability of their inhabitants are defined as "absolute extreme". Such environments can serve as terrestrial models for the last stages of life in the history of Mars, when the surface cooled down and atmosphere and water disappeared. The cryptoendolithic microbial community in porous rocks of the Ross Desert in Antarctica and the microbial mats at the bottom of frozen Antarctic lakes are such examples. The microbial communities of Siberian permafrost show that, in frozen but stable communities, long-term survival is possible. In the context of terraforming Mars, selected microorganisms isolated from absolute extreme environments are considered for use in creation of a biological carbon cycle.
 
Article
All forests in the Italian Alps have been affected by humans in some way, either through direct periodic destruction of the forest or by more subtle forms of management and habitat manipulation. For this reason it is very difficult to find stands with “old-growth properties°d. However, in the last century there has been a noticeable reduction in many human activities in the mountains and, as a result, many forest stands have developed naturally over the past few decades, even if their composition and structure still reflect past human activity. This makes it particularly important to study the unmanaged parts of previously managed forests: the past history, present structures and long-term monitoring of these forest stands are fundamental steps for increasing our knowledge of the natural forest stand dynamics. Knowledge of this sort is an important reference tool for the present and future development of near-natural silviculture aimed at producing commodities as well as maintaining environmental values. In this paper, a case study in the forest of Paneveggio is presented. In this forest, a strict forest reserve of about 100 ha was established, and a long-term forest dynamics study was set up in four 1-ha plots. The main results of the study of the stand histories of these plots are presented, and their current naturalness status is discussed.
 
Article
The sub-alpine belt in the south-eastern Alps, is characterized by the presence of numerous chamaephytic and nanophanerophitic communities. The structure of these formations is homogenous and dominated by few species such as: Pinus mugo, Rhododendron sp. pl., Juniperus communis subsp. alpina, Genista radiata, Erica carnea subsp. carnea and Calluna vulgaris. The flora, however, is heterogeneous, because in this ecotonal belt there is the influence of many different vegetation classes. The syntaxonomic scheme proposed tries to combine the significance of these two fundamentals elements in the phytosociological method. Twelve associations are considered and two of them (Rhodothamno chamaecisti-Juniperetum alpini and Vaccinium vitis-idaeae-Callunetum vilgaris) are described here for the first time.
 
Article
Relationships between plant communities and the physical environment during primary succession on recently deglaciated glacier forelands were studied in 3 areas of the Italian Alps. The aim of the research was to relate traditional phytosociological data with environmental variables. Twenty-eight phytosociological relevés were performed, each associated with twenty-six environmental variables; quantitative parameters of richness and diversity were also calculated. Species/relevés, environmental variables/relevés and species/environmental variables matrices were analyzed by cluster analysis, PCA and Spearman correlation coefficient. Three main stages of succession were identified by floristic composition and confirmed by environmental parameter evaluation. A complex of environmental variables seems to be closely correlated with terrain age and richness/diversity parameters, even though diversity decreases in late successional stages. The phytosociological significance of species is in accordance with their position in the context of succession.
 
Article
We investigated the senescence of flag leaves of durum wheat ( Triticum durum ) during grain-filling, and of petal-like ray flowers of Jerusalem artichoke ( Helianthus tuberosus ) at anthesis. In both systems, we observe cleavage of DNA to high molecular weight fragments, followed by further degradation to nucleosomal fragments (laddering), a classical hallmark of apoptosis. We show that DNA fragmentation in such specialised leaves is triggered early in organ development, before the appearance of visual symptoms of senescence. Our observations support the hypothesis that senescence and cell death are part of the plant developmental program, activated by developmental cues.
 
Article
A computerised image analysis system was used to investigate several root morphological parameters in young seedlings of broom ( Spartium junceum L.) and manna ash ( Fraxinus ornus L.) growing in three different environmental conditions: slope, terrace and plane. Data show that slope, to a greater extent than terrace, affects the root system of both species by increasing significantly the length and number of root apices of first-, second- and third- order lateral roots. Besides these variations in morphological parameters, the overall architecture of the root system results modified on a slope. In fact, an asymmetrical distribution of lateral roots was observed around the tap root and along two main directions: up-slope and down-slope. The morphological parameters, analysed separately on the two portions of the root system, present significant differences. The following hypothesis is put forward: in response to a slope, the two species reinforce their anchorage strain by changing the organisation of the root system, particularly in the up-slope direction. In these two species, the occurrence of slight differences in response to a slope suggests that plant anchorage might require species-specific adaptations.
 
Article
The composition of the volatile fraction in selected aromatic plants of the Lamiaceae from garrigue sites in southern France is described. Calamintha nepeta appeared heterogeneous. The oil was dominated by piperitone oxide, and piperitenone oxide or by pulegone and menthone. In Nepeta nepetella , nepetalactone, almost exclusively the (4a-α, 7α, 7a-β)-isomer, made up more than 85% of the essential oil. Dichloromethane extracts from Teucrium polium contained germacrene D or sabinene as main components, α-pinene, β-pinene and β-caryophyllene in varying proportions as further important constituents, and various minor components depending on the origin.
 
Article
The relative electrolyte leakage (REL) method is often used to assess the frost hardiness of plant organs. However, testing the frost hardiness of roots with REL yields different results when the roots are frozen while remaining in the soil or in some other substrate than when REL follows a freezing test made on excised root segments. In this study, we show that the electrolytes may already leak out of injured roots during freeze/thaw treatment and during washing of the roots after the treatment. In this case, the conductivities measured after the freezing test and killing of the tissue both give lower readings than expected for injured samples, and hence the results of the REL are incorrect. We suggest that roots should be washed free of soil and placed in test tubes prior to the freezing test. The leakage of electrolytes from injured roots to soil may also limit the use of the REL method for measuring root viability.
 
Article
Although developmental instability (DI), measured as fluctuating asymmetry (FA), is expected to be positively related to environmental stress and negatively to habitat quality, the pattern found here was the reverse. Developmental instability of leaf traits (leaf width and vein distances within a leaf) was estimated (using two indices of FA: FA 4 and σ i 2 ) and compared between three populations of Plantago major L. (Plantaginaceae) from northern Serbia. Two of the populations are from chronically polluted areas (Karaburma & Zemun), while Crni Lug is from an unpolluted, natural area. Results obtained using both FA indices were the same; higher asymmetry levels in the unpolluted area than in the polluted sites, were found for both traits. Between the two polluted sites, FA values were significantly higher in Karaburma site for vein distances within a leaf. Concerning differences in FA 4 values between samples, in two cases, results are similar to those found for σ i 2 values, for vein distances within leaf. These are the first quantitative data on P. major indicating that (i) plants living in the stressful sites are more symmetrical and (ii) leaf FA for plant species with wide ecological distribution such as P. major should be considered as an `index of habitat quality.'
 
Article
Callus production from leaf explants of Azadirachta excelsa (Jack) Jacobs was favoured by Murashige and Skoog medium supplemented with 4 mg l -1 indole-3-butyric acid (IBA) and 1 mg l -1 6-benzyladenine (BAP). Increasing the concentration of BAP to 2 mg l -1 induced shoot regeneration. Adding polyvinylpyrrolidone (PVP) to the medium resulted in a significantly increased number of shoots. Transfer onto medium containing 0.5 mg l -1 BAP, 0.4 mg l -1 gibberellic acid (GA 3 ) and 2% sucrose stimulated elongation of the internodes; subsequent transfer onto medium containing 1 mg l -1 IBA induced root formation. The histological analysis demonstrated that organogenesis and embryogenesis occurred in the same callus. However, shoots originated inside the callus mass, whereas the embryos originated on the surface. Given that the embryos did not develop beyond the globular or heart-shaped stage, we concluded that the plants regenerated from callus were derived only from organogenesis.
 
A simplified scheme of the possible pathways of UDP-GlcA synthesis. Only enzymes discussed in the text (UDPGDH and myoinositol oxygenase) are shown. 
Article
UDP-d-glucuronic acid (UDP-GlcA) is a key intermediate in the synthesis of other UDP-sugars and also an important glucuronosyl donor for cell wall polysaccharide synthesis. UDP-GlcA can be synthesised via two routes in plants: the myo-inositol oxidation pathway and a pathway involving UDP-glucose dehydrogenase (UDPGDH)-catalysed oxidation of UDP-glucose (UDP-Glc). This review discusses the synthesis of UDPGlcA within the context of cell wall biosynthesis.
 
Article
Genome variation in tissue culture is of importance for commercial use in plant propagation as well as for basic research on plant growth and development. RAPD fingerprinting can be used to trace genetic or epigenetic changes at the genome level. In the present paper, results of RAPD analyses on primary tissue cultures are given with particular attention to the repeatability of the method. The significance of primer binding site competition for the discovery of qualitative and quantitative DNA polymorphism is discussed.
 
Proplastids with membranes (arrow) and plastoglobules (p), in a cell from yellow part of green leaf. Bar= 0.5 pm. Figure 21.
4 . Figure l. Sa&n in blossom. Bar = 3 cm. Figure 2. Different developmental stages of saffron used for the research. (a) floral bud; @) green leaves; (c) mature flower with basal colourless ovary (arrow); (d) colourless style, yellow-red at the lower part and red stigmas (e). Bar=2 cm. Figure 3. Whole dormant corms. Longitudinal section of corm showing white starchy parenchyma is in the insert. Bars = 1 p. Figure 4. Fresh red stigmas from saffron flower at anthesis. Bar= 0.25 cm.
Article
Saffron (Crocus sativus L. Iridaceae) chromoplasts and other plastids were studied by electron microscope to determine their structure, origin and pigment localization. Plastids from pistils of floral buds and flowers at anthesis, dried and decoloured stigmas, and green and senescent leaves were examined. Results indicated that mature saffron chromoplasts occur in the red parts of stigmas and have a reticulo-tubular structure. They contain a reticulum of tubules and plastoglobules. Tubules formed dilated vesicles mainly while plastoglobules appeared numerous and scattered on the whole chromoplast. Chromoplasts appeared in red stigma of very young floral buds. They originated from amyloplasts, the only plastids occurring in the colourless basal portion of style, as well as in the parenchyma of ovary and corm. Transition forms of plastid as amylo-chromoplast, occur in the yellow parts of stigma and style. Senescent leaves did not show plastids with structure similar to the chromoplast of red stigma. Red pigmented and scented stigmas might cooperate in saffron reproduction by attracting pollinator.
 
Article
Transglutaminases (TGs) are a multigenic family of calcium-dependent protein cross-linking enzymes, which are present in animal and plant cells. We have previously reported the presence of TGs in the cytosol and, more recently, in the cell wall of Malus domestica pollen, where it may be involved in pollen germination and pollen-stylar interactions. In this report we describe a simple method for the in situ visualisation of TG activity in germinating pollen. The method is based on the incorporation, mediated by pollen TG, of a fluorescently labelled exogenous diamine substrate of TG (fluorescein-cadaverine) into endogenous pollen substrates. Following the in situ TG activity reaction, the presence of cross-linked pollen proteins was visualised in fixed specimens of germinated pollen by laser confocal microscopy. Our data indicate the presence of TG cross-linking activity mainly at the apical part of the pollen tube, in the region proximal to the grain, and in the pollen grain itself. In planta, the products of this activity may provide strength to the pollen tube migrating through the style.
 
Assessment of energy balance closure. Daily average fluxes of net radiation (R n ) minus the soil heat flux (G) are compared against the sums of sensible (H EC ) and latent heat (L v E EC ) measured by the eddy covariance system over a citrus orchard irrigated by drip irrigation (upper) and by flooding irrigation (lower).  
Actual ET a estimated by the single approach versus the one measured by the eddy covariance system over the citrus orchard irrigated by drip irrigation (upper) and by flooding irrigation (lower) by using the K c values given in FAO-56.  
Actual ET a estimated by the dual approach versus the one measured by the eddy covariance system over the citrus orchard irrigated by drip irrigation (upper) and by flooding irrigation (lower) by using the K cb values given in FAO-56.  
Computed crop coefficient by the FAO-56 single and dual crop coefficient approaches for a citrus orchard irrigated by drip irrigation (upper) and by flooding irrigation (lower). Crop coefficients suggested by FAO-56 (Kc-FAO-56) are plotted in the same figures. DOY ¼ day of year.
Comparison between the measured crop coefficients over the two sites, one irrigated by drip irrigation and the other by flooding irrigation.
Article
The aim of this study was to use the FAO-56 single and dual crop coefficient approaches to estimate actual evapotranspiration (ETa) over an irrigated citrus orchard under drip and flood irrigations in Marrakech, Morocco. The results showed that, by using crop coefficients suggested in the FAO-56 paper, the performance of both approaches was poor for two irrigation treatments. The Root Mean Squared Error (RMSE) between measured and simulated ETa values over the citrus orchard under drip irrigation was about 1.43 and 1.27mm/day for the single and dual approaches, respectively, while the corresponding statistics for the orchard irrigated by the flooding technique was 1.87 and 2.48mm/day. After determination of the appropriate values of the crop coefficient (Kc) based on eddy covariance measurements of ETa, the performance of both approaches greatly improved. The obtained Kc values were lower than the FAO-56 values by about 20%. The low Kc values obtained reflect the practice of drip irrigation for one field and the low value of cover fraction for the other field. Additionally, the efficiency of the irrigation practices was investigated by comparing the measured Kc for two fields. The results showed that a considerable amount of water was lost by direct soil evaporation from the citrus orchard irrigated by flooding technique.
 
Article
The objective of this research was to determine the functional responses of a cultivated, agro-forestry system, namely a poplar plantation, to actual and future atmospheric CO2 concentrations. Hence, this research has combined a fast growing, agro-forestry ecosystem, capable of elevated biomass production, with a large-scale Free Air Carbon Enrichment (FACE) system, one of the few available in the European Union on a forest tree stand. The FACE facility is located close to a natural CO2 source and is drawing scientists from several European countries, and from other continents, to closely cooperate and combine their scientific efforts on the same experimental system. Furthermore, this FACE apparatus utilizes a novel technology, originally developed by Italian institutions, based on the release into the atmosphere, at sonic velocity, of pure CO2 instead of an air-CO2 mixture. The research activities conducted at the POPFACE site, on the responses of the tree plantation to future atmospheric conditions, have integrated observations at the leaf level, such as photosynthesis, respiration and transpiration, with measures carried out at the whole-tree and stand scale, such as canopy architecture, light interception and biomass production. Finally, the ecosystem dimension has also been analysed by studying root productivity and soil processes, host – parasite interactions, and carbon sequestration throughout a rotation cycle of the stand.
 
Article
This paper presents an interdisciplinary approach to crop improvement that links physiology with plant breeding and simulation modelling to enhance the selection of high-yielding, drought-tolerant varieties. In a series of field experiments in Queensland, Australia, we found that the yield of CIMMYT wheat line SeriM82 ranged from 6% to 28% greater than the current cultivar Hartog. Physiological studies on the adaptive traits revealed that SeriM82 had a narrower root architecture and extracted more soil moisture, particularly deep in the profile. Results of a simulation analysis of these adaptive root traits with the cropping system model APSIM for a range of rain-fed environments in southern Queensland indicated a mean relative yield benefit of 14.5% in water-deficit seasons. Furthermore, each additional millimetre of water extracted during grain filling generated an extra 55 kg ha-1 of grain yield. Further root studies of a large number of wheat genotypes revealed that wheat root architecture is closely linked to the angle of seminal roots at the seedling stage - a trait which is suitable for large-scale and cost-effective screening programmes. Overall, our results suggest that an interdisciplinary approach to crop improvement is likely to enhance the rate of yield improvement in rain-fed crops.
 
Map showing the three riparian populations of P. alba studied in northern Italy (Ticino) and central Italy (Cesano to the east and Paglia-Tevere to the west). The background shows the main biogeographical regions of Italy according to the EEA biogeographical map of Europe (2001), including the biogeographical subdivision due to the Appenine mountain range.
Article
White poplar (Populus alba) is a widespread species of the northern hemisphere. Introgressed populations or hybrid zones with the related species of the European aspen (Populus tremula) have been suggested as potential venues for the identification of functionally important variation for germplasm conservation, restoration efforts and tree breeding. Data on the genetic diversity and structure of introgressed P. alba are available only for sympatric populations from central Europe. Here, clonality, introgression and spatial genetic patterns were evaluated in three riparian populations of P. alba along the Ticino, Paglia-Tevere and Cesano river drainages in Italy. Samples of all three populations were typed for five nuclear microsatellite markers and 137 polymorphic amplified fragment length polymorphisms. Microsatellite-based inbreeding co-efficients (FIS) were significantly positive in all three populations. Genetic diversity was consistently highest in Ticino, the population with the highest level of introgression from P. tremula. Population differentiation (FST) was low between the Ticino valley in northern Italy and the Cesano valley in central Italy and between the central Italian populations of Cesano and Paglia-Tevere, consistent with a role of the Appenine mountain range as a barrier to gene flow between adjacent drainage areas. Introgression was not the primary determinant of within-population spatial genetic structure (SGS) in the studied populations.
 
Article
A phylogenetic analysis was performed based on ITS DNA sequences of fourteen samples from different sources of six species of Salicornia, the three allied genera Arthrocnemum, Sarcocornia and Halocnemum of the same tribe Salicornieae , and other genera of the subfamily Salicornioideae used in previous studies. Bassia hirsuta, Camphorosma monspeliaca (subfamily Chenopodioideae ) and four species of Suaeda (subf. Suaedoideae ) were chosen as outgroups. Results show that the annual genus Salicornia is a sister group to the perennial genera Sarcocornia, Arthrocnemum and Halocnemum . Moreover, the phylogenetic analysis based on ITS results distinguished two groups of Salicornia species which fitted with ploidy level: one group consisted of diploid species, and the second of tetraploid ones. Sarcocornia and Arthrocnemum are shown to be closely related, even though the species investigated here exhibited an evident distance between their ITS sequences. On the basis of our results, these two genera should be united. Bienertia (already separated as Bienertieae ) was confirmed as probable outgroup to the subf. Salicornioideae , while Kalidium (subf. Salicornioideae , tribe Halopeplideae ) was an outgroup to the rest of the Salicornioideae (tribe Salicornieae ). The group Allenrolfea plus Halocnemum was the most basal of the tribe Salicornieae amongst those investigated in this study. The two samples of Halocnemum strobilaceum used in this work displayed numerous changes (transitions and transversions) in their respective sequences, probably related to their morphological and chorological differentiation. On the basis of our analysis, the most probable basal chromosome number for Salicornieae appears to be 2n = 18. The same number would also be the base number for the annual genus Salicornia and the perennial Arthrocnemum ( + Sarcocornia ), with polyploidy arising independently in the two groups.
 
Article
Many Aloe species are exploited as natural products. Generally, the leaves are unsustainably picked from wild plants to meet the market demand. Basic scientific information on seed biology and the ways of increasing levels of secondary metabolites in seedlings is still lacking for Aloe species. This study investigated seed germination requirements and evaluated levels of secondary metabolites in seedlings of Aloe arborescens, an important species in traditional medicine. The highest percentage germination (78%) and the fastest germination rate (GR) (10% d− 1) with a mean germination time (MGT) of 9 days were achieved at 20°C under a 16-h photoperiod. At 25°C, maximum percentage germination (67%) (P − 1) and shorter MGT (6 days) were obtained under constant light. These results indicate that temperature and light play a significant role in germination of A. arborescens seeds. Increasing osmotic pressure on seeds decreased percentage germination, whereas buffering the solution to a range of pH values (4–10) did not significantly affect germination. Smoke–water (1:500 v/v), smoke-isolated karrikinolide (10− 8 and 10− 9 M) and potassium nitrate (10− 3 and 10− 4 M) significantly promoted germination compared with the control at 25°C (supra-optimal temperature) under a 16-h photoperiod. These treatments were also effective in increasing secondary metabolite levels (flavonoids and phenolics) in A. arborescens seedlings.
 
Article
A multi-proxy palaeoenvironmental study (pollen, non-pollen palynomorphs-NPP, macrocharcoal particles) of a small fen located in the Perafita valley (2240 m a.s.l, eastern Pyrenees, Andorra) was undertaken to trace prehistoric human activities related to woodland clearance and past land-uses at high altitudes. The results of this study constrained by 9 AMS radiocarbon measurements are combined with archaeological data and compared with similar research carried out at the same altitude in the adjacent Madriu valley (Andorra). The overall objectives of this article are, first, to formulate different chronological patterns and spatial land-use distribution at a micro-regional scale during prehistory and, second, to discuss different drivers of prehistoric occupation models in the eastern Pyrenean highlands. The palaeoecological study of the Planells de Perafita fen was performed at high temporal resolution, allowing us to focus on detailed prehistoric (mainly Mesolithic and Neolithic) and Bronze Age human activity. It demonstrates that the shaping of this cultural landscape is the result of a long-term land-use history, which began at the late Mesolithic/early Neolithic transition onwards (ca 6400–6100 cal BC). The existence of three main phases of ‘‘inter-valley'' land-use variability has also been highlighted, thus testifying a complex and heterogeneous upland land-use model during the Neolithic and Bronze Age. These land-use variabilities between the two adjacent Andorran valleys provide the basis for a discussion of the way in which environmental constraints influenced prehistoric land-use spatial organisation and of how the interaction between environmental (including climatic parameters), socio-economic and cultural conditions affected the temporal and spatial dynamics of landscape shaping in the eastern Pyrenean highlands.
 
Location of the study area (Salinas and Aguada Blanca National Reserve) within the Arequipa and Moquega Departments, in the southern Peruvian Andes. 
Dendrogram showing the results of hierarchical clustering. Subclusters Ia (1 –23), Ib (24–39), IIa (40–54) and IIb (55–70) group the vegetation relev  ́s carried out in sites A1, A2, B1 and B2, respectively. 
Ordination diagram of the PCoA, showing a separation between vegetation relev  ́s of area A (in the right part) and of area B (in the left side). Axes 1 (linked to environmental gradient) and 2 (linked to disturbance intensity) explain 31% and 13% of the total variance, respectively. 
Box-whisker plot showing the range of PVs for each subcluster (Ia, Ib, IIa and IIb) indicated by the cluster analysis. The upper and lower levels of the box represent the 75th and 25th percentiles and the whiskers represent the 90th and 10th percentiles. The open circle represents an outlier. The solid line represents the median.
Article
In the Peruvian highlands, climate change and inadequate management are causing land degradation and collapse of the pastoral system. Our research project was aimed at assessing the impact of grazing on dry Puna ecosystem, as understanding and predicting vegetation changes in harsh environments in the face of different disturbance regimes is required for aware and effective management. The study area was the Salinas and Aguada Blanca National Reserve. Two experimental areas were selected, characterized by deep soils with gentle slopes and by shallow soils with steeper slopes. In each area, sites with low and high disturbance regimes were identified, and vegetation was sampled using 10 × 10 m plots. The results indicated that the environmental constraints have a marked influence on the species composition, while disturbance quantitatively affects diversity. The floristic changes observed under different disturbance intensities are mainly related to the functional differentiation of the plant communities and to the decrease in vegetation cover. These processes pose a serious risk to the livelihood of the local people, because they can lead to the loss of biodiversity and economic value of pastures, as well as to soil erosion.
 
(a) Mass spectrum of delphinidin 3,5 diglucoside, recorded at 18.077 min. (b) Mass spectrum of petunidin 3,5 diglucoside, recorded at 21.703 min.  
Relative positions of the developmental stages of B. officinalis flowers (Korba and Beja) based on their essential oils composition (Tables II and III) in the space defined by the three principal components.  
Article
The aim of this study was to examine the chemical composition and antioxidant activities of the essential oils and anthocyanin of Borago officinalis flowers. At the flowering stage, the essential oil yield in Korba (0.95 ± 0.03%) was higher than that in Beja (0.29 ± 0.03%, w/w). The essential oil composition was characterized by high proportions of (E,E)-decadienal, the main compound of monoterpene aldehydes class. The reverse phase–high-performance liquid chromatography–mass spectrometry analysis indicated that flower anthocyanins were extracted and analysed for the first time and petunidin 3,5 diglucoside (58.8% in Korba and 54.93% in Beja) was the major anthocyanin followed by delphinidin 3,5 diglucoside (36.45% in Korba and 44.45% in Beja). During the development of borage flower, anthocyanin yield increased significantly (P Keywords: Antioxidant activities; Borago officinalis; anthocyanins; essential oil; flower development Document Type: Research Article DOI: http://dx.doi.org/10.1080/11263504.2013.778349 Affiliations: 1: Laboratory of Bioactive Substances, Biotechnology Center in Borj-Cedria Technopol, Hammam-Lif, Tunisia 2: Departimento di Ingegneria dell'Innovazione, Università del Salento, Lecce, Italy Publication date: May 4, 2014 $(document).ready(function() { var shortdescription = $(".originaldescription").text().replace(/\\&/g, '&').replace(/\\, '<').replace(/\\>/g, '>').replace(/\\t/g, ' ').replace(/\\n/g, ''); if (shortdescription.length > 350){ shortdescription = "" + shortdescription.substring(0,250) + "... more"; } $(".descriptionitem").prepend(shortdescription); $(".shortdescription a").click(function() { $(".shortdescription").hide(); $(".originaldescription").slideDown(); return false; }); }); Related content In this: publication By this: publisher By this author: Salem, N. ; Msaada, K. ; Hammami, M. ; Limam, F. ; Vasapollo, G. ; Marzouk, B. GA_googleFillSlot("Horizontal_banner_bottom");
 
Article
When assessing the conservation status of narrow endemic plants, life history traits must be taken into account, since endemics combine small population ranges and sizes, and long persistence with limited reproductive and dispersal ability. In this paper, we present the global assessment of the conservation status of a narrow endemic plant from the Sardinian-Corsican biogeographic province, by applying IUCN criteria and categories, together with an evaluation of some reproductive traits. Centaurea horrida Badarò (Asteraceae) is an endemic species of northern Sardinia (Italy). It is protected by the Bern Convention (Appendix I) and listed as priority species by the “Habitat” Directive (92/43/EEC, Annex II). The species appears in the 1997 IUCN Red List as “Vulnerable” (VU). With the aim of evaluating the risk of extinction and of providing management tools for the network of protected areas in which this species is present, some reproductive traits have been evaluated, and the distribution, size and structure of its population have been measured according to IUCN 2006 Guidelines. Centaurea horrida is not able to self-pollinate and its effective seed dispersal ability is limited. Its extent of occurrence is 172.43 km<sup>2</sup> and its area of occupancy is 108 km<sup>2</sup>. Population size has been estimated at 11,719 adult individuals. Significant differences in adult densities among sites have been highlighted. The structure of the population is dominated by adult individuals (on average 68%), while the proportion of seedlings is only 7% on average. Its habitat underwent an extinction rate of 18% in 50 years. On the basis of the data gathered, the status to be assigned to C. horrida is that of “Endangered” (EN). This first attempt to evaluate the conservation status of a narrow endemic plant from the Sardinian-Corsican biogeographic province allowed us to conclude that the management of rare species must be site-specific and that there is urgent need to acquire detailed data on endangered species, especially within biodiversity hotspots, and to continuously update Annex II of the EU Habitat Directive and the IUCN Red List.
 
Article
Hieracium busambarense (Asteraceae), a new species from calcareous-dolomite cliffs of Rocca Busambra (western Sicily, Italy) is described and illustrated here.
 
Article
The new agaricoid species Inocybe aureocitrina, belonging to section Rimosae, is described and illustrated based on morphological and ecological characters. It is recognized by the pale citrine yellow when young to golden yellow or orange yellow pileus colour at maturity, habitat in evergreen oak calcareous forests and especially by the rather small spores, broadly ellipsoid and not reniform in profile. A comparison with the holotypes of two close taxa with yellowish colours, e.g. Inocybe obsoleta var. lutea and Inocybe fastigiata var. cerina, is presented. Illustrations of the macro- and micro-morphological features of this new species are given.
 
Map of the sampling sites: the chosen vineyards are located in the Conegliano Valdobbiadene area, North-East of Italy (star); vineyard 1, Pescatori farm; vineyard 2, Conte Collalto farm; vineyard 3, Carmina farm; vineyard 4, Marchiori farm; vineyard 5, Rolle farm vineyard 6, Ruggeri farm. 
Endophyte quantification of the first sampling on May 2011: the amounts of endophytes isolated from tissues (root, leaves and shoot) of chosen grapevine plants in vineyards are expressed as log of cell number per gram of organ FW. Values are the mean of three replicates and standard deviations are shown. 
Endophyte quantification of the first and second samplings concerning only epigean tissues: data are expressed as log of cell number per gram of leaf FW. The values are the mean of three replicates and standard deviations are shown. 
Article
Endophytes are micro-organisms that colonize the internal tissues of plants without inducing signs of negative effects and that can provide benefits to plant health and yield. In the present work, the culturable bacterial endophyte community, colonizing vegetative organs of grapevine, was isolated from surface-sterilized plant tissues and characterized by molecular methods. From roots, shoots and leaves of Vitis vinifera “Glera”, located in six different vineyards throughout the Conegliano-Valdobbiadene DOCG area (Veneto, Italy), 381 culturable strains were successfully isolated; amplified ribosomal DNA restriction analysis and nucleotide sequencing showed that approximately 30% of the endophyte community belonged to the genus Bacillus, which was the most represented; other genera such as Staphylococcus, Microbacterium, Paenibacillus, Curtobacterium, Stenotrophomonas, Variovorax, Micrococcus and Agrococcus were identified. Endophyte community composition within each vine was different in respect to other endophyte populations living in grapevine plants coming from different vineyards; moreover, the bacterial composition changed depending on the season of sampling. The above data highlight the great diversity of culturable bacterial species inhabiting Glera grapevines and open the way for a characterization and selection of strains that could potentially be used to improve the vineyard management for plant growth and yield, plant responses to stresses, biocontrol and biofertilization.
 
Article
The role of vegetation analysis by remote sensing (RS) and Geographical Information System (GIS) technology to support plans for sustainable development is discussed through a proposal of an index of ecosystem “integrity” or of regeneration capacity. The index is based on the vegetation “mass” of a given land cover type and the capacity that such mass has to contrast soil erosion. The index is therefore taking into account the effects of human activities and not merely the state of ecosystems in terms of their components. It would be very difficult, if not impossible, to calculate the proposed index without RS and GIS techniques. These allow, respectively, to collect and to analyze the spatial data at relative low cost and in relatively short times. Time and money are the limiting factors for all the management plans. As an example of application, we have calculated the index for the Santos estuary drainage basin (Brazil) selected as a case study within the ECOMANAGE project funded by European Commission. The area was chosen because of its great economic importance and for relevant environmental problems (industrial pollution and urbanization pressure) that could limit the development. For estimating the relative vegetation mass, we have used the Leaf Area Index, while for the soil erosion, we have used the revised universal soil loss equation model. The maps of ecosystem integrity produced by the application of the index may be very useful to guide the planners in the development of the urbanization process that is threatening the “Mata Atlantica” and the mangrove forests.
 
Article
Using the example of Madagascar Fauna and Flora Group (MFG), we look at the factors which contribute to the successful maintenance of an international consortium dedicated to the conservation of Malagasy biodiversity. We discuss the philosophy, mission and set-up of the MFG and how, over its 25-year history, it has enabled the productive collaboration of its diverse international members to achieve the common goal of helping to protect Madagascar's unique biodiversity. We explore the benefits of pooling resources to fund a stable base of personnel and infrastructure to maximise the conservation impact of contributions from organisations that might not otherwise be able to fund viable independent programmes and consider the benefits that accrue to partners in the consortium. We highlight specific examples of plant conservation projects set up as a result of the productive working relationship between MFG and Missouri Botanical Garden to reinforce the argument that like-minded organisations working in successful partnership can far exceed the conservation capacity of individual institutions.
 
Article
UNFCCC's “Cancun safeguards” (COP 16, 2010) provide a strong call for comprehensive steps to prevent harm to biodiversity from Reducing Emissions from Deforestation and forest Degradation (REDD+) activities and to support its conservation. However, as non-binding “principles” and due to their general wording, they are not operational in the present form. Additionally, the scientific literature on biodiversity monitoring for REDD+ is still very limited, particularly when it comes to REDD+ in tropical forests and at the national scale. Whereas some authors suggest that biodiversity integration can be achieved by means of standardised protocols and techniques, others consider that an effective monitoring of biodiversity in tropical forests at the national scale may be an impossible task to achieve in a cost-effective way. However, recent research offers some functional approaches to tackle the many challenges involved. This paper explores the perspectives and limits of developing and effectively incorporating appropriate biodiversity objectives and indicators in Papua New Guinea's multipurpose National Forest Inventory (PNG's NFI). The PNG's NFI is currently being designed under the UN-REDD programme as a key component of the National Forest Monitoring System that PNG is required to establish in order to participate in a future REDD+ mechanism. We conclude that the challenge cannot be effectively tackled only at the design stage of the NFI, as it needs to address a number of issues related to different stages of the REDD+ preparedness process:
 
Effect of pH variation on NADP-ME activity of Vetiveria zizanioides DEAE-extracts. Assays were performed with 5.0 mM malate and 0.5 mM NADP+. Enzyme acrivities are expressed in pKat mg? prot. The points are experimental data. The lines are the results of the best fit of the experimental data to the following equation: v = kw,,/O+ [H+]/K, + K/[H+]). 
Effect of temperature on NADP-ME enzyme activity. The inset shows the Arrhenius plot of the data in a temperature range from 20 to 45°C. 
FIG URE 2-H igh magnification of a bundle sheath chloroplast from V. zizanioides, show ing immunolabelling against Rubisco. Colloidal gol d particles strongly label the stroma. For controls see Figure Je. Scale bar = 0.5 J-Im. 
Article
Leaf anatomy (light and transmission electron microscopy), immunogold localization of Rubisco, photosynthetic enzyme activities, CO2 assimilation and stomatal conductance were studied in Vetiveria zizanioides Stapf., a graminaceous plant native to tropical and subtropical areas, and cultivated in temperate climates (Northwestern Italy). Leaves possess a NADP-ME Kranz anatomy with bundle sheath cells containing chloroplasts located in a centrifugal position. Dimorphic chloroplasts were also observed; they are agranal and starchy in the bundle sheath and granal starchless in the mesophyll cells. Rubisco immunolocalization studies indicate that this enzyme occurs solely in the bundle sheath chloroplasts. Pyruvate-orthophosphate dikinase, NADP-dependent malate dehydrogenase (NADP-MDH), NADP-dependent malic enzyme (NADP-ME), PEP-carboxykinase and NAD-dependent malic enzyme (NAD-ME) activities were determined. Enzyme activity and some kinetic properties of NADP-ME and NADP-MDH as well as CO2 compensation point and stomatal conductance values were calculated indicating a NADP-ME C4 photosynthetic pathway. Biochemical and structural results indicate that V. zizanioides belongs to the C4 NADP-ME variant. This plant appears to be well adapted to the varying environmental conditions typical of temperate climates, by retaining high enzyme activities and a low CO2 compensation point.
 
Article
Waterlogging decreased carotenoids content of Vigna sinensis and Zea mays whilst salinity provoked increases in former and decreases in later. Both treatments showed significant reductions in chlorophylls content and in photosynthetic activity (Hill reaction and <sup>14</sup>CO<sub>2</sub>-light fixation). A significant decrease in the activity of ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) was detected in both plants. These reductions could result in losses in photosynthetic activity with a drop in the net formation of carbohydrates. Waterlogging markedly increased glucose and sucrose in shoots and roots of both plants throughout the experimental period but greatly decreased polysaccharides , whilst salinity reduced all carbohydrate fractions. Foliar application of 50 ppm kinetin to treated plants mostly counterbalanced the observed changes in pigments as well as in Hill reaction and <sup>14</sup>CO<sub>2 </sub>assimilation. Also kinetin rendered levels of carbohydrate fractions in shoots and roots of treated plants and activity of Rubisco most likely to reach control values. The increased levels of glucose and sucrose concomitant with decreased polysaccharides might point to a block in their transport rather than from an over production. Kinetin counterbalanced the effects of waterlogging or salinity on photosynthetic activity, probably through more production of enzyme and/or delay of senescence.
 
Article
Mitotic chromosomes of 12 species of Catasetum were assessed to contribute with the karyotypic study of the subtribe Catasetinae (Orchidaceae), expanding the knowledge of this group in terms of chromosomes and supporting its taxonomic and evolutionary analysis. The species are maintained in cultivation in the greenhouse of the Department of Plant Biology/IB/UNICAMP and in the “Orquidário Frederico Carlos Hoehne” of the Botanical Garden of São Paulo. Chromosome counts ranged from 2n = 54 to 2n = 108. Karyotypes were prepared for all species studied, in which there was a predominance of metacentric chromosomes and some submetacentric ones. The chromosome size ranged from 0.5 to 4.9 μm, the total chromosome length ranged from 34.7 to 78.7 μm and the asymmetry index TF% ranged from 21.2 to 42.3. The results obtained so far favor the taxonomy of the genus, allowing to distinguish species with very similar external morphology.
 
The number of somatic embryo in MS proliferation medium, added with NAA (5.37 lM) and various BAP concentrations (40–50 mg embryogenic callus was used and data were scored after 7th week of culture). 
Callus biomass growth in different cultural environments. MS medium contained 4.52 lM 2,4-D (100 mg i.e. 0.1 g embryogenic callus was used).  
Maturation of somatic embryos in MS medium added with 2.60 lM GA 3 , data were scored after 4 weeks of culture. 
Plantlet recovery time (day) in different culture environments. 
Article
The genus Zephyranthes rosea is a member of the family Amaryllidaceae. The plant is widely cultivated as ornamental. The objective of this study was to optimize an in vitro propagation method for the production of genetically stable Z. rosea plant. The chromosomal status of the regenerated plants was also studied to determine their ploidy levels and to identify the structural and numerical variations, if any. Two explants of Zephyranthes rosea, i.e. bulb scale and flower bud (3–4 mm each), were used and incubated in a culture room at 25 ± 2°C in which two different types of calli were induced from two sources. The MS medium amended with 2,4-dichlorophenoxyacetic acid (2,4-D) (0.5–2.0 mg/l) successfully induced callus from bulb-scale explants (50.25–57.5%). The addition of coconut water (10%) in 2,4-D-added medium further improved the callus induction frequency (68.4%). Bulb-scale calli were found to be highly regenerative while flower-bud calli did not show any organogenetic responses. The use of plant growth regulators, such as naphthaleneacetic acid (NAA) + benzylaminopurine (BAP), was found to be very effective for shoot bud development; maximum shoot number (11.50/callus mass) was observed in NAA (0.5 mg/l) + BAP (1.0 mg/l) added medium. Histological analysis of callus revealed that the origin of the shoot bud was de novo. Rooting frequency (65.25%) and the number of roots (7.5/shoot) were best achieved in indole-3-butyric acid (4.0 mg/l)-amended medium, followed by indole-3-acetic acid (4.0 mg/l). The regenerated Z. rosea plants showed 2n = 24 chromosome numbers.
 
Location of the area under study.  
Composition of plant categories for each group of assemblages.  
Article
This research was undertaken with the aim of improving our knowledge of the floristic composition and spatial-temporal dynamics of plant communities in Mediterranean temporary wet habitats, and to evaluate the diversity and conservation relevance of their plant assemblages. Three different types of temporary wet habitats were monitored throughout the growing season: large temporary ponds (lTPs), small temporary ponds (sTPs), and rock pools (RPs). lTPs presented a small-scale zonation arranged in an inner, an intermediate, and a peripheral belt. A total of 98 species were recorded, of which 40 were classified as temporary wet habitat (TWH) specialists and 24 as rare. Eight different groups of plant assemblages were identified presenting space-time dynamics related to water-depth variations and flooding period. In terms of diversity, the most relevant assemblages were located in the outer belt of the lTPs and in the sTPs. The mosaic of different assemblages and their time-variability determined the presence of several types of habitats of community interest according to the Habitat Directive. This wide heterogeneity should be taken into account to ensure that all types of TWHs are considered in conservation programmes.
 
Article
With the increased loss of plant biodiversity, the Ex situ seed conservation has become of strategic importance. International treaties and conventions encourage more developed countries to cooperate in providing financial and other supports for the establishment and maintenance of Ex situ conservation facilities in developing countries. In this regard, the Nepal Academy of Science and Technology (Nepal) and the Ev-K2-CNR (Italy) set up the Himalayan Seed Bank, with the goal of establishing Ex situ seed conservation facility of rare, endemic and endangered plants in Nepal. Here, we discuss the importance of training on seed curation, management and research for the seed bank operators in developing countries. Particular attention is given to the procedures for providing power supply and for optimizing seed longevity in dry storage. Finally, the importance of duplicates in high-standard international seed banks is also discussed.
 
Article
Two new species, Virgariella lodoicea and Cacumisporium oceanicum and a new record of Diplocladiella scalaroides from Seychelles islands are proposed. A species of Helicosporium which could not be determined is also described.
 
Article
Human-induced and natural stress factors can affect fine roots and ectomycorrhizas. Therefore they have potential utility as indicators of environmental change. We evaluated, through meta-analysis, the magnitude of the effects of acidic deposition, nitrogen deposition, increased ozone levels, elevated atmospheric carbon dioxide, and drought on fine roots and ectomycorrhizal (ECM) characteristics. Ectomycorrhizal colonization was an unsuitable parameter for environmental change, but fine root length and biomass could be useful. Acidic deposition had a significantly negative impact on fine roots, root length being more sensitive than root biomass. There were no significant effects of nitrogen deposition or elevated tropospheric ozone on the quantitative root parameters. Elevated CO2 had a significant positive effect. Drought had a significantly negative effect on fine root biomass. The negative effect of acidic deposition and the positive effect of elevated CO2 increased over time, indicating that effects were persistent contrary the other factors. The meta-analysis also showed that experimental conditions, including both laboratory and field experiments, were a major source of variation. In addition to quantitative changes, environmental changes affect the species composition of the ectomycorrhizal fungal community.
 
Mean SRL values (±SE) for ECM (A) and fine roots (<2 mm) (B) in coniferous and deciduous tree species. There is a tenfold difference in the scale of the y-axis, between A and B.
Correlation analysis between SRL and the latitudes of Picea abies and Fagus sylvatica fine roots (<2 mm). Trendline is added only for Picea abies.
Correlation analysis between SRL and soil pH of Picea abies ECM.
Influence of the sampling method on the mean SRL values (±SE; ±1.96 × SE) of three fine-root diameter classes.
Meta-analysis of treatment effects on the SRL response ratio: mean values and 95% CI. The analyses summarize data from deciduous and coniferous trees, all sampling methods in pots and in the field, and root diameter classes <0.5, <1, 1 – 2, and <2 mm.
Article
Specific root length (SRL, m g-1) is probably the most frequently measured morphological parameter of fine roots. It is believed to characterize economic aspects of the root system and to be indicative of environmental changes. The main objectives of this paper were to review and summarize the published SRL data for different tree species throughout Europe and to assess SRL under varying environmental conditions. Meta-analysis was used to summarize the response of SRL to the following manipulated environmental conditions: fertilization, irrigation, elevated temperature, elevated CO2, Al-stress, reduced light, heavy metal stress and physical disturbance of soil. SRL was found to be strongly dependent on the fine root classes, i.e. on the ectomycorrhizal short roots (ECM), and on the roots <0.5 mm, <1 mm, <2 mm and 1 - 2 mm in diameter SRL was largest for ECM and decreased with increasing diameter. Changes in soil factors influenced most strongly the SRL of ECM and roots <0.5 mm. The variation in the SRL components, root diameter and root tissue density, and their impact on the SRL value were computed. Meta-analyses showed that SRL decreased significantly under fertilization and Al-stress; it responded negatively to reduced light, elevated temperature and CO2. We suggest that SRL can be used successfully as an indicator of nutrient availability to trees in experimental conditions. Keywords: Environmental conditions; fertilization; fine root morphology; indicator; specific root length; stress
 
Article
In this paper we present a comprehensive inventory of the non-native vascular flora of Italy, which was produced within the project “A survey of the Italian non-native flora”, funded by the Italian Ministry for the Environment. Previously published floristic accounts were the main source of information. Historical records were critically revised and integrated with recent literature, data from herbaria and some unpublished information, so as to obtain a complete, up-to-date catalogue of the non-native vascular plant species that occur spontaneously in Italy. The inventory lists 1023 non-native species and subspecies, which account for 13.4% of all the Italian flora. The Italian non-native flora was divided, according to its residence time, into 103 archaeophytes and 920 neophytes. According to its current invasion status, it was classified into 437 casual (42.7% of all non-native) and 524 established taxa, the latter being divided into 361 naturalized non-invasive (35.3%) and 163 invasive taxa (15.9%). The inventory includes a group of 62 species (6.1%) that lack recent records (i.e. since 1950). By combining local expertise into a unified, nationwide scheme using a standardized method and terminology, the inventory provides the essential scientific basis for the development of plant invasion research and management in the country.
 
Possible arrangement of domains in a pectin-xyloglucan complex, based on the model of Keegstra et al. 1973. 
Possible arrangement of domains in a pectin-xyloglucan complex, in which xyloglucan forms the backbone of the complex, based on the suggestion of Abdel-Massih et al. (2003). 
Possible arrangement of domains in a pectin-xyloglucan complex, in which xyloglucan is linked to the arabinan in RG-I sidechains, based on current evidence. 
Article
Evidence for covalent pectin – xyloglucan linkages in the cell wall of growing cells and maturing tissues has been reported. In-vitro studies using isolated Golgi membranes, and pulse-labelling studies in vivo, indicate that pectin – xyloglucan linkages form in the Golgi apparatus. The structure and biological significance of these complexes are discussed.
 
Article
Differences between various inherent physiological characteristics of lateral roots and of taproots of faba bean plants (Vicia faba L.) have been described in the literature. The question as to whether distinct bacterial communities inhabit each of those root types calls for further investigation. This question was tackled using aeroponically grown plants, i.e., plants that were grown under conditions as homogeneous as possible. Samples of the apical 5 cm of taproots and of lateral roots were compared. Metabolic fingerprints of root bacterial communities were analyzed using the Biolog® assay. Specificity of colonization of the different root types by specific bacterial taxa was examined by the Real-Time Polymerase Chain Reaction (PCR) method. Root bacterial communities produced distinct metabolic fingerprints for each of the two root types. Herbaspirillum spp. were found to be associated with lateral roots but not with taproots both under non-saline and saline (50 mM NaCl) conditions. No significant differences were found in the abundance of bacteria with respect to either root type or salinity. It is concluded that different root types, even within single root systems, differ not only in their physiological traits but also in their bacterial associations. Such associations might have adaptive advantages.
 
Article
A new species of Centaurea, C. sakarensis, known from a single locality north-east of the village of Lessovo on Mt Sakar, is described and illustrated. It belongs to C. sect. Acrolophus, and its morphologically closest relative is C. cariensis Boiss., a Turkish endemic from western and south-western Anatolia. The new species is currently known from a single population of about 1000 individuals, growing on open stony calcareous places, at 475 m a.s.l., and should be classified as Critically Endangered, (B1ab[i, ii, iii]+2ab [i, ii, iii]).
 
Comparison of the urban bryophyte diversity among selected European cities (data follow Frahm 2006a (Rolandseck), Pokorny et al. 2006 (Trento), Zechmeister et al. 2001 (Vienna), Esteve et al. 1977 (Granada), Mazimpaka et al. 1988 (Madrid), Rams et al. 2000 (Murcia), Fudali 1998 (Szczecin) and Vanderpoorten 1997 (Brussels/Bruxelles)).
Article
In this study, the urban bryophyte flora of the city of Cologne (W. Germany) was studied. A total of 143 bryophyte taxa (17 hepatics and 126 mosses) were recorded within the metropolitan area of Cologne. Three species were newly recorded for North Rhine-Westphalia: Hannediella heimii, Schistidium helveticum and Tortula schimperi. Thirteen species red-listed in NRW were recorded, among them hardly endangered: Bryum intermedium and Syntrichia laevipila and extinction endangered: Syntrichia papillosa. The temperate biogeographic element prevails among Cologne bryophytes. According to frequency of recordance, only 11 species are widespread over the urban area of which three are hepatics.
 
Flower of L. cavanillesii (a) and Cucurlionidae in a flower (b).
Fruit set of L. cavanillesii at the Botanical Gardens of Valencia (a) and Cova Alta Microreserve (b) resulting from pollination treatments testing for autonomous self-pollination (ASP), hand self-pollination (HSP), hand cross-pollination (HCP), agamospermy (AGP) and control (CTRL). Bars are means.  
Article
Knowledge about the reproductive system of species inhabiting rocky habitats is scarce. The reproductive biology (floral biology, experimental pollination, insect visits, inbreeding depression, and seed predation) of the rupicolous Linaria cavanillesii was analyzed under field and experimental conditions. Self-compatibility was revealed by the high fruit set, seed set, and seed mass in the pollination experiment. Furthermore, results disclose that this species does not need insect visitors for seed production since fruit set after autonomous self-pollination was similar to that by hand cross-pollination. Self-offsprings were not affected by a strong degree of inbreeding depression in early life-cycle stages. Seed predation by Cucurlionidae is the main limiting factor of fruit and seed production in this species. Contrary to other perennial species of Linaria previously studied, L. cavanillesii represents the first clear report of self-fertility.
 
Location of sampling area and distribution of soil sampling points.  
Spatial distribution of soil salinity at different depths.  
Article
Soil salinization constitutes an environmental hazard worldwide. The Bohai Sea coastal wetland area is experiencing dramatic soil salinization, which is affecting its economic development. This study focused on the spatial variation and distribution characteristics of soil salinity in this area using geostatistical analysis combined with the kriging interpolation method, based on a large-scale field investigation and layered soil sampling (0–30, 30–60 and 60–100 cm). The results revealed that soil salinity in these layers demonstrated strong variability, obvious spatial structure characteristics and strong spatial autocorrelation. Soil salinity displayed a significant zonal distribution, gradually decreasing with increasing distance from the coastline. Apart from the northern part of the study area, which appeared to be not affected by soil salinization, there were varying degrees of soil salinization in nearly 70% of the total area. With increasing soil depth, the areas of non-salinized and mild salinized soil gradually decreased, while those of moderate salinized and strong salinized soils increased. The area of saline soil first decreased and then increased. The study area could be divided into four management zones according to soil salinities in the top 1-m soil body, and utilization measures, adapted to local conditions, were proposed for each zone. The results of our study present an important theoretical basis for the improvement of saline soils, for wetland re-vegetation and for the sustainable utilization of soil resources in the Bohai Sea coastal wetland.
 
Article
Fast-atom bombardment mass spectrometry (FABMS), and collisionally-induced dissociation and mass-analyzed ion kinetic energy spectrum scanning (CID/MIKES) have been used to examine cation effects on a Phaseolus chloroplast complex phosphodiesterase activity. The kinetic parameters of the activity, and the effects of Li + , Na + , K + , Mg 2+ , Mn 2+ and Fe 3+ upon them, were determined with 3',5'-cyclic AMP, -GMP and -CMP, and 2',3'-cyclic AMP, -GMP and -CMP as substrates. Irrespective of the presence of cations and of the complex nucleotidase, the preferred substrate is a 3',5'-cyclic nucleotide, not a 2',3'-cyclic nucleotide. In the presence of the nucleotidase 3',5'-cyclic AMP and 3',5'-cyclic GMP are the best substrates, unless Fe 3+ ions are present. Mg 2+ and Mn 2+ stimulate hydrolysis of 3',5'-cyclic AMP and 3',5'-cyclic GMP by the complex. However, Fe 3+ inhibits these activities but stimulates the hydrolysis of 3',5'-cyclic CMP. Kinetic data indicate that each of these six substrates is hydrolyzed at a single, common, catalytic site. Differentiation of the phosphodiesterase isomeric mononucleotide products by FABMS CID/MIKES analysis indicates that in the absence of ions and after removal of the nucleotidase, the 3'-ester linkage of the 3',5'-cyclic substrates was hydrolyzed exclusively. Addition of monovalent and divalent ions results in hydrolysis of both the 5'- and 3'-ester linkages.
 
Article
Olea europaea L. is one of the oldest domesticated tree species. O. europaea varieties cannot be confused because they are very different in morphology, genetics, and secondary metabolite content. It is important to study and establish the genetic structure of vegetal cultivars to better distinguish them, to solve past misclassification, to preserve plant biodiversity, and to increase their use, diffusion, selection, resistance to adversities, marketing, and scientific applications. Five simple sequence repeat loci (DCA-3, DCA-9, UDO99-9, UDO99-35, and EMO-3) were used to differentiate 39 individuals, representing 13 olive cultivars sampled in Latium (Central Italy). The markers showed a high discrimination power and were able to differentiate 39 alleles. Observed heterozygosity ranged from 0.538 at locus UDO99-9 to 1 at locus UDO99-35, with a mean value of 0.784. DCA loci were the most informative ones. Sample clustering, based on their genetic distance and similarity values, produced a phylogenetic network that has shown a unique major group of cultivars, composed of two sub-branches, and two independent taxa.
 
Article
To study salt dynamics in soil profiles under different groundwater conditions, a 3-year indoor experiment was carried out under conditions of open-air evaporation. Silt loam soil was treated under three groundwater table depths (0.85, 1.05, and 1.55 m) combined with three groundwater salinities: 0.40 dS m− 1 (2 g l− 1), 0.80 dS m− 1 (4 g l− 1), and 1.60 dS m− 1 (8 g l− 1). A total of nine soil columns (0.14 m internal diameter) were used to simulate different combinations of groundwater depths and salinities. The results obtained showed that salt first accumulated at the bottom of the soil column, and only when soil salinity in this layer had remained relatively stable with time, salt began to accumulate in the adjacent upper soil layers. When all subsoil layers had reached dynamic salinity equilibrium, electrical conductivity (EC) of soils in the surface layer began to increase drastically. With increasing salt accumulation in the surface soil, EC of the subsoil began to rise tardily. The further up the soil layer, the earlier EC started to increase, although the redistribution of salts in the soil profile tended to be homogenous. Groundwater depth did not significantly change subsoil EC values at the same depth; however, it distinctly affected the time needed for the subsoil to reach dynamic salinity equilibrium. Groundwater salinity, on the other hand, did not significantly alter the time point at which soil salinity at the same depth began to increase rapidly or the time period needed to reach dynamic salinity equilibrium. This study explored salt transport processes in the soil profile through a long-term experiment, enabling us to reveal some general laws governing salt dynamics that will be very important to understand the mechanism of soil salinization. The results could be further used to set up strategies to prevent salinization or to improve salt-affected soils.
 
Article
The Vernonieae tribe presents strong taxonomic delimitation problems as it is considered one of the most complex groups of the Asteraceae family, comprising approximately 1100 species distributed across 129 genera. In this study, a comparative analysis of the Vernonieae species was performed to understand the events involved in the chromosome evolution of these species and to further deduce their taxonomy. The representatives were cytogenetically characterized via analyses of morphology, karyotype asymmetry and differential staining with fluorochromes CMA and DAPI as well as FISH. According to morphometric data, all species showed symmetrical karyotypes with prevailing metacentric chromosomes, even in species belonging to different genera. Variability in diploid chromosome number was detected (2n = 18 to 2n = 60), and chromosome sizes were observed to be between 1.00 and 4.09 μm. Additionally, variation in the pattern of heterochromatin was observed mainly in relation to CMA+ bands, in which the number varied from 4 to 16 heterochromatic regions. Only one species, Vernonia scorpioides, presented positive DAPI bands, which were located in the terminal position in most of the chromosomes. The differences in the sizes and quantities of heterochromatic bands may be related to small structural rearrangements during karyotype evolution of the Vernonieae tribe.
 
Top-cited authors
Carlo Blasi
  • Sapienza University of Rome
L. Poldini
  • University of Trieste
Fabio Conti
  • University of Camerino
Simonetta Peccenini
  • Università degli Studi di Genova
Simonetta Fascetti
  • Università degli Studi della Basilicata