Dr. Josef Pančić

Ohne Zusammenfassung     

Dr. Josef Pančić

Ohne Zusammenfassung     

Verbascum Pančićii m. hyb. nov.

Ohne Zusammenfassung     

Zur systematischen Stellung vonValeriana pancicii Halácsy &Baldacci undV. bertiscea Pančić

Summary Morphological and ecological studies as well as investigations of essential oils reveal thatValeriana pancicii Hal. &Bald., an endemic of southern Montenegro, must be considered a subspecies ofValeriana celtica. ThusV. celtica includes 3 subspecies: subsp.celtica (subsp.pennina Vierh.) endemic in the western, subsp.norica in the eastern Alpes and subsp.pancicii in Montenegro (Abb. 2). While the two alpine subspecies are polyploids, subsp.pancicii proved to be diploid on x=12, and may be supposed to stand closest to the ancestor of theV. celtica-complex. The occurence of subsp.pancicii in Montenegro seems to indicate an East Mediterranean-montane descent of the complex.A comparison ofValeriana montana L. andV. bertiscea Pan., described from Montenegro on the basis of herbarium specimens, and a study of populations on the locus classicus hardly justify taxonomic separation fromV. montana.     

Composition, antimicrobial and antioxidant activity of the extracts of Eryngium palmatum Pančić and Vis. (Apiaceae)

The chemical composition, antimicrobial and antioxidant activity of Eryngium palmatum, an endemic plant species from the Balkan Peninsula, were investigated. The flavonoids apigenin (9.5±0.3 mg g^?1) and apigenin 7-O-glucoside (2.4±0.1 mg g^?1) were determined in a methanol extract of aerial parts using HPLC analysis. The methanol extract of roots contained catechin (5.0±0.1 mg g^?1), epicatechin (2.9±0.1 mg g^?1), chlorogenic acid (1.6±0.0 mg g^?1), gallic acid (0.9±0.0 mg g^?1) and rosmarinic acid (0.9±0.2 mg g^?1). GC-FID and GCMS analysis of a chloroform extract of aerial parts showed that the main volatile constituents were falcarinol, linoleic acid, hexadecanoic acid and methyl linoleate (comprising 32.6%; 24.4%; 19.9; 13.2% of the volatile fraction, respectively), while octanoic acid, tetradecanol and dodecanol dominated in the chloroform extract of the roots (34.9%; 25.8%; 22.2% of the volatile fraction, respectively). Investigation of antimicrobial activity by broth microdilution showed that the methanol and chloroform extracts of aerial parts and roots exerted a significant effect (MIC 3.5–15.6 μg mL^?1) against tested Gram-positive and Gram-negative bacteria. The methanol extracts of aerial parts or roots exerted moderate ferric reducing antioxidant power, DPPH radical scavenging activity and hydroxyl radical scavenging activity.     

Benzyladenine induction of buds and somatic embryogenesis in Picea omorika (Pančić) Purk.

Somatic embryogenesis and adventitious bud formation, initiated from shoot explants of Picea omorika is described. Benzyladenine (BA) as the only growth regulator, added to modified Von Arnold and Eriksson medium, induced formation of both adventitious buds and embryogenic tissue. Optimal BA concentration for bud induction was 4.5 M and further bud development and plantlet formation was achieved on growth regulator-free medium. The embryogenic tissue formation was induced when the explants were first grown on the medium with high BA content (22.5 M) and then transferred to medium without growth regulators. Subsequent proliferation of embryogenic tissue was accomplished by subculturing on medium containing 9 M 2,4-dichlorophenoxyacetic acid and 4.5 M BA, and further embryo development was achieved on medium with 12 M abscisic acid. Embryos cultured on growth regulator-free medium formed roots and rooted plantlets were successfully established in soil in the greenhouse.     

Morphological Studies of Rhaphidopteris hsüi sp. nov

The present paper deals with the cuticular structure of Rhaphidopteris hsüi sp. nov. The specimens were collected from the Upper Triassic cos series of Liuzhi district, Guizhou Province. Based on the shape and cuticular structure of leaf and segments, this new species is assigned to Corystospermaceae of Cycadofilicales. According to the assemblage of the fossil plants, the writers consider that the geological age of this flora is assigned to the middle Keuper-Rhaetic stage of Late Triassic.     

Urban Development Consequences on the Wetland Ecosystems Transformations—Case Study: Pančevački Rit,Serbia

The article analyzes the consequences of one century long human influences on vegetation of the wetland ecosystem, on the example of Pan?eva?ki Rit in Belgrade, Serbia. The autochthonous, non-altered ecosystem was formed in the alluvial plain between Danube and Timis River in the formation of connected swamps and bogs with periodically flooded patches. The major transformation of the wetland ecosystem started with the construction of the embankment and dense canal system followed by settlements development, increasing of population density, intensification of agriculture activities etc. The study area transformation factors were identified in the first phase of research, while the second phase includes analyses of their influences on habitat conversion using GIS, with the purpose to preserve fragments of indigenous wetland vegetation, mostly fragile wetland meadows from further degradation.     

Morphological variation and population structure on the island of Korčula,Yugoslavia

A comparison of head and body morphology on the ecologically uniform island of Korčula provides a good example of the balance that occurs in microevolution between selective pressures toward homogenization and selective inertia toward heterogeneity. thirty-eight measurements were made from a sample of 471 males and 526 females. Head variables, being more eco-stable than body variables, remain relatively more different between two distinct populations (eastern and western villages) than do the more eco-labile body variables, although both do vary significantly between east and west. The differences apply to both men and women. These east-west contrasts reflect the differential migration of Slavs to the island over the past three centuries, with a new wave of immigrants settling mainly in the east and introducing a new gene pool to the pre-existing Slavic hybrid population which had settled the island in the sixth to the eighth centuries. In addition to the predominant east-west differences in morphology, we also find significant variation between all villages in both head and body variables. We conclude that this is an indication of the considerable reproductive isolation that has persisted between all villages until the post-World War II period. This paper is a part of a study conducted with financial suport from the joint Yugoslav-United States Board for Bilateral Research, as a common Institute for Medical Research and Occupational Health (Zagreb) and Smithsonian Institution (Washington, DC) research, projects JFP-429 and JFP-674.     

Relations of cell wall bound peroxidases,phenols and lignin in needles of Serbian spruce Picea omorika (Pančić) Purkynĕ in the natural habitat

The habitat of Picea omorika (Pančić) Purkynĕ, Serbian spruce, is characterized by extremely variable environmental conditions. Relations between the activities of cell wall bound peroxidase (POD) and contents of lignin and cell wall bound phenols were studied in needles of Serbian spruce, in the natural habitat on Mountain Tara. We intended to see, by using Redundancy Analysis, if the yearly peaks of activities of cell wall bound enzymes correspond to the cell wall bound phenols and lignin contents, and whether this relation contributes to the adaptation of Serbian spruce to severe habitat. The highest lignin content was found in spring and it was in high positive correlation with the activities of five covalent POD isoforms. The contents of cell wall bound phenols were lowest in spring and higher in summer and autumn, being in high positive correlation with ionic POD isoforms. The results indicate that relation found between ionic POD isoforms and cell wall bound phenols, as well as between covalent isoforms and lignin may be related to the environmental conditions.     

Ecological filters and variability in stream macroinvertebrate communities: do taxonomic and functional structure follow the same path?

We examined the community-environment relationships of lotic macroinvertebrates in near-pristine headwater streams, and the correlation between patterns in taxonomic and functional structure at two regional extents. The across-ecoregion scale comprised five ecoregions spanning all of Finland, while the within-ecoregion scale comprised of north boreal and middle boreal ecoregions. We expected that taxonomic structure should exhibit stronger relationships than functional structure to spatial gradients, while the reverse should be true for local environmental factors. We found some support for this notion, because spatial variables were marginally more important for taxonomic than functional structure. Furthermore, within the two ecoregions, local environmental variables were slightly more important for functional than taxonomic structure. Geographical location (i.e. spatial variables) was more influential at the across-ecoregions extent than within the two ecoregions. Largely the same local environmental variables accounted for variation in both taxonomic and functional structure, including water pH, nutrients, colour, and stream size. Similar responses to local environmental features likely contributed to the significant correlation between patterns in taxonomic and functional structure. It has been suggested that functional traits may be rather insensitive to natural variation, yet our functional categorization showed distinct variation along local environmental, catchment, and spatial gradients across near-pristine streams. Thus, natural ecological filters should be accounted for prior to the examination of the effects of anthropogenic filters on stream macroinvertebrate community structure.     

Morphological variability in the ecotone — an important factor for the conservation of fish species richness in Swiss rivers

Data from a survey on the distribution of fish species in Switzerland were used to test the hypothesis that species richness of the fish fauna is closely related with the structure, heterogeneity and complexity of the ecotonal zone in rivers. Species richness increased with increasing structural heterogeneity and variability of the ecotone in rivers wider than 2.5 m at altitudes below 500 m. In lowland brooks and in rivers at higher altitudes other factors seemed to be more important than morphological variability: alpine rivers are more often left natural than lowland rivers and salmonid stocking is more important in these naturally species poor fish communities. The proportion of threatened species was higher if riverbed and -banks were natural, the slope was flat, the variability in depths and sediment composition was high and if the ecotonal zone was well structured. Specialized species such as nase and riffle minnow only occurred in larger rivers, whereas in small and medium-sized rivers with low morphological variability these threatened species were missing. On the other hand, ubiquitous species such as chub, roach and perch, occurred in all sizes of rivers, even if morphological variability was small. Low morphological variability and its impact on the composition of the fish community is mainly a consequence of past human interventions. Therefore river management has to take into account the ecological requirements of specialized species and increasing the variability of riverbed and banks would considerably contribute to the conservation of endangered fish species.     

Morphological variation in adult chimpanzees (Pan troglodytes verus) of the Taï National Park, Côte d'Ivoire

Twenty five adult chimpanzee skeletons (Pan troglodytes verus) of known age and sex (15 females, 10 males) from a long‐term study site in Taï National Park, Cote d'Ivoire present new data on variation. These skeletons provide a rare opportunity to measure the cranium and postcranium from the same individuals. We compare measurements and indices of the Taï sample with those of relatively complete Pan troglodytes schweinfurthii skeletons from Gombe National Park, Tanzania. Measurements of Pan paniscus are included as an outside comparison. The Taï and Gombe samples are analyzed by sex; combined sex samples are compared between the two groups, and the two sexes to each other. Taï females and males do not differ in most long bone lengths or in pelvic dimensions, but do differ significantly in cranial capacity, facial measurements, clavicle length, scapular breadth, and femur length. Gombe females and males differ significantly in some facial measurements and in scapular breadth. In combined sex samples, Taï individuals have lower cranial capacity, longer palate and mandible, and greater dimensions in the trunk and limb lengths. Taï females account for most of the variation; males differ from each other only in greater length of humerus and femur. The Taï skeletons provide new data for assessing individual variation and sexual dimorphism within and between populations and species. The combination of cranial and postcranial data provides a clearer picture of chimpanzee intraspecific and interspecific variation than can be gained from either data set alone. Am J Phys Anthropol, 2008. © 2007 Wiley‐Liss, Inc.     

The evolution of aggression: can selection generate variability?

Three models--the war of attrition, the size game and the badges of dominance game--are described, in which natural selection can maintain genetic variability for aggression. The models differ in whether or not the traits that settle contests are costly in contexts other than fighting, and also in whether signals are used. It is concluded that contests will be settled by non-costly traits only if the value of the contested resource is small relative to the cost of fighting, and that 'honest' signalling of aggressiveness is stable only if individuals giving signals that are inconsistent with their behaviour suffer costs. The literature on 'badges of dominance' in birds is reviewed. New data on great tits, greenfinches and corn buntings show that there is plumage variability within age and sex that sometimes serves to settle contests, and that, in the first two species but not the third, the badges are uncorrelated with size, and settle contests only over trivial resources.     

Latitudinal gradient of taxonomic richness: combined outcome of temperature and geographic mid‐domains effects?

For several decades, the origin and ecological consequences of large-scale continental and marine Latitudinal Gradients of Taxonomic Richness (LGTR) have been intensively debated. Among the various hypotheses, it has been proposed that a LGTR is the by-product of a geographic mid-domain effect, i.e. the result of a random distribution of ranges of taxa between physical hard boundaries such as the continent/ocean interface. In order to more realistically evaluate the role of the mid-domain effect on the origin and evolution of the LGTR of marine planktonic organisms, we present a 2D model based on a cellular-automaton approach in which sea surface temperatures (SST) and currents are forced in the biogeographic dispersal of a randomly generated clade (a 2D 'geophyletic' model). Sensitivity experiments allow to evaluate the effects of currents, SST and the geographical origin of a clade on the formation and shape of a LGTR for planktonic organisms when coupled with a geographic mid-domain effect. Results are discussed in the light of the empirical LGTR of extant planktonic Foraminifera in the Atlantic Ocean. Independently of any other biotic or abiotic parameter, inclusive of the surface currents and origination/extinction absolute and relative rates, our simulations show that the coupling of the mid-domain effect with two critical parameters, namely the shape and intensity of the SST gradient and the geographic origin of a clade, produces realistic patterns of diversity when compared with the observed LGTR of extant atlantic planktonic foraminifera. The results illustrate a non-linear relation between a unimodal latitudinal SST gradient and a resulting bimodal LGTR characterized by a drop in species richness near the equator. This relation indicates that the SST gradient exerts a mid-domain effect on the LGTR. The latitudinal positions of the modal values of the LGTR are also found to be influenced by the geographic origin of the simulated clade.     

Isolation and endemism in subterranean aquatic snails: unexpected case of Montenegrospeum bogici (Pešić et Glöer, 2012) (Gastropoda: Truncatelloidea: Hydrobiidae)

Hydrobiologia - The subterranean aquatic snails may serve as a model of endemism and isolation vs. migration in subterranean habitats. The aim of the present paper is to verify the hypothesis that...