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Nuovi allestimenti ed organizzazione nel museo dell'orto botanico di napoli

Applicazione di tecniche di carbonizzazione artificiale per lo studio di fossili vegetali

ID:1458

ID 174

A new calcareous-dolomitic horizon of a platy-dolomite type (sensu BERNIER, 1994), containing the remains of a Cenomanian continental palaeoflora, is reported. The platy-dolomite crops out in the Mount Chianello carbonate ridge (sheet tav. I.G.M. 1:25.000, 198 IT S.W. - Castel San Lorenzo), dominating the village of Magliano Vetere (SA). This ridge is a deformed part of a Mesozoic-Cenozoic platform (campano-lucana platform in D'ARGENIO et alii, 1973; apenninic platform in MOSTARDINI & MERLINI, 1986). A 200 m thick interval of the sequence has been sampled in order to date this platy doloinite. On the basis of facies, it has been divided into four intervals which are, from bottom to top: a) 50 m stromatolitic dolomite and limestones below the platy dolomite, showing the sedimentological features of a restricted lagoonal environment in an inner carbonate platform. Among the microfossils, Sellialveolina viallii COLALONGO, Nezza-zata simplex OMARA, Pseudolituonella reicheli MARIE, Biplanata peneropliformis HAMAOUI & SAINT-MARc and Pseudorhapydionina dubia (DE CASTRO) are present. This fossil assemblage indicates in age ranging from the base of the Cenomanian up to the middle Cenomanian (DE CASTRO, 1991). b) 70 m thin-bedded dolomite and dolomitic limestones of which the typical platy dolomite facies constitutes 40 m in which sets of millimetre-scale laminae are frequently present and often contain terrestrial floral remains on the laminae surfaces. The fossi-liferous horizon is ascribed to the middle-upper Cenomanian by, the presence of Nezzazata simply OMARA, Biconcava bemori HAMAOUI & SAINT-MARC, Biplanata peneropliformis HAMAOUI & SAINT-MARC Chrysalidina gradata D'ORBIGNY, Pseudorhapydionuna dubia (DE CASTRO), Pseudorhapydionina laurinensis (DE CASTRO). The sedimentological features of the platy-dolomite and fossil flora content suggest deposition in a tidal flat under upper- intertidal-supratidal conditions and, in particular, in an algal-marsh environment often exposed to dessication and storms, located close to a coastal area with primeval Angiosperms and Conifers. The first palaeontolological studies on this continental flora, allow its to ascribe some fossils to Sapindopsis sp.. c) 42 m limestones and bioturbated dolomite which, marks a drastic change in the environmental and sedimentological conditions on the carbonate platform, with heavily bioturbated bioderrital material (namely fragments of Rudists), often in massive lavers, proving a swift transition to deeper open marine conditions. In particular, the first 18 metres of this interval have many traces of Thalassinoid bioturbation. The tracks and burrows give an unmistakable appearance to the rocks and make this an important marker horizon in the whole ridge of Mount Chianello-Mount Vesole. Because of the presence in thin section of Dicyclina sp., Cisalveolina fraasi (GLMBEL) and Pseudorhapydionida casertana (DE CASTRO), a late Cenomanian age is assigned to this interval. d) 43 m of limestones and dolomite. The sedimentological features indicate an open carbonate platform emironment often with coarse biodetrital elements and in the upper part, a tendency to the emersion. This interval has been assigned to the Turonian by the presence of Murgeina apula (LUPERTO-SINNI). Biconcava bentori HAMAOUI & SAINT MARC and small Moncharmontia apenninica (DE CASTRO). In conclusion, the above observations show that the sequence including the platy dolomite of Magliano Vetere, ranges in age from the Lower Cenomanian to the Turonian. The flora of the platy dolomite is Middle Cenomanian in age and reflects an upper intertidal-supratidal environment. The plant remains ascribed to the genus Sapindopsis constitute the first Italian finding of this type and fit well with a shallow marine environment close to a coast line. The studied sequence documents peritidal or paralic environments with a restricted water circulation in the Lower Cenomanian, with a strong tendency to stagnation in the Middle Cenomanian (platy dolomite). The restricted conditions change drastically in the Upper Cenomanian with its bioturbated rudist fragment-rich horizons. As other similar horizons in the Mesozoic carbonatic sequences of the Southern Apennine (BRAVI, 1995), the platy dolomite of Magliano Vetere seems to fit well, due to its age, with a marked eustatic sea level minimum in the Middle Cenomanian; tis minimum is recognizable in the 3degrees order eustatic curve of HAO el alli (1987). As a final considerations, it could be said that the studied sequence is relevant to two important currents of research: The analysed stratigraphic imerval, because of its quality and thickness, is particularly appropriate for studies of the enironmental and ecological changes in carbonate shallow water platforms during the global anoxic event at the Cenomanian-Turonian (C/T) boundary, at present the object of important research (ERBA et alii; 2001; FORSTER et alii, 2001: KOLONIC et alii, 2001, WALSWORTH-BELL et alii, 2001). In the succession studied the Cenomanian Turonian boundary is located between the intervals c and d (see fig. 3). This transition represents a short period during which, in the neritic realm, strong environmental change and an important evolutionary overturn are associated. In the hydrocarbon context, the main source rocks in the Italian sedimentary sequences are constituted by organic-rich intervals deposited in shallow carbonate platform environments or in deep water interplatform basinal settings (KATZ et alii, 2000). Although similar rocks are present in a number of different stratigraphic levels, only those in the Upper Triassic-Lower Triassic (accumulations of Malossa, Rospo and Gela), Middle Triassic (accumulation of Villafortuna) and Upper Cretaceous (Monte Alpi) are at present known to have generated oil. Detailed geochemical studies (KATZ et alii, 2000) indicate that there is a sharp contrast in the stable isotope composition of the organic matter contained in the different Italian carbonate source rocks. The Triassic and Toarcian organic matter is isotopically light (delta C-13(bitumen)

stampato a settembre 2006

The morphology of leaves is shaped by both historical and current selection acting on constrained developmental systems. For this reason, the phylogenetic signal of these characters is usually overlooked. Methodology. We investigate morphology of the leaflets of all genera of the Zamiaceae using multiple microscopical techniques to test whether leaf characters present a phylogenetic signal and whether they are useful to define clades at a suprageneric level. Pivotal results. Our investigation shows that most genera are quite uniform in their leaflet anatomy, with the largest genera (Zamia, Encephalartos) presenting the highest degree of variation. Using both Bayesian and parsimony methods on two different molecular scaffolds, we are able to show that leaflet anatomy has a strong phylogenetic signal in the Zamiaceae and that many clades retrieved by molecular analyses present potential synapomorphies in their leaflet anatomy. Particularly, the placement of Stangeria in a clade with Zamia and Microcycas is supported by the presence of both an adaxial and an abaxial girder sclerenchyma and the absence of sclerified hypodermis. The placement of Stangeria as sister to Bowenia, on the other hand, is not supported by our analysis. Instead, our results put into question the homology of the similar guard cell morphology in the two genera. Conclusions. We show that leaflet anatomy has a substantial amount of phylogenetic signal in the Zamiaceae, supporting relationships that are not supported by general morphology. Therefore, anatomical investigation represents a promising avenue for plant systematists.

PREMISE Unlike most flowering plants, orchid flowers have under-developed ovules that complete development only after pollination. Classical studies reported variation in the stage in which ovule development is arrested but the extent of this variation and its evolutionary and ecological significance are unclear. METHODS Here, we performed light microscopy observations and surveyed the literature gaining information on 94 orchid species including tropical and temperate members of all subfamilies as well as species with contrasting pollination strategies (rewarding versus deceptive) and life forms (epiphytic versus terrestrial). We analysed the data using statistical comparisons and a Phylogenetic Generalized Least Square (PGLS) analysis. KEY RESULTS Apostasioideae, the sister to the rest of the orchids, have mature ovules similar to other Asparagales, while under-differentiated ovules are present in the other subfamilies. Ovule developmental stages showed high variation even among closely related groups. Ovules were more developed in terrestrial than in epiphytic, in temperate than in tropical, and in rewarding than in deceptive pollination orchid species. This latter comparison was also significant in the PGLS analysis. CONCLUSIONS These results suggest that ovule developmental stage in orchids can be shaped by ecological factors, such as seasonality and pollination strategy, and can be selected for optimizing female reproductive investment. This article is protected by copyright. All rights reserved.

Heterotrophic components of biofilms on wood artefacts were studied at the Conservation Laboratory for Wood Artefacts of the University Suor Orsola Benincasa of Naples, Italy. The aim of the study was to add new information on the micro-habitats represented by biofilms formed by wood-dwelling organisms. Light and electron microscopy of histological features of woods used to make the artefacts showed that the woods belonged to species of lime (Tilia sp.), poplar (Populus sp.) and pear (Pyrus sp.). A Denaturing Gradient Gel Electrophoresis analysis performed on heterotrophic microorganisms colonizing the artefacts led to identify four species of bacteria, namely Bacillus cereus, B. mycoides, B. subtilis and Microbacterium oleivorans, and seven species of fungi, namely Alternaria alternata, Aspergillus fumigans, A. versicolor, Cladosporium cladosporioides, C. oxysporum, Fusarium oxysporum and Penicillium chrysogenum. Based on its morphological features, an insect found on some artefacts was identified as the xylophagous beetle Nicobium castaneum (Anobiidae). The influence of wood type and environmental conditions on the diversity of microorganisms was discussed.

In sexually deceptive orchids, pollinator specificity is the main factor responsible for species isolation. The two sexually deceptive orchids Ophrys chestermanii and Ophrys normanii occur sympatrically on Sardinia and attract the same pollinator, males of Bombus vestalis, by producing the same odour bouquets. Since gene flow between these two species has been shown to be almost absent, their genetic distinctness seems to be preserved by other forms of reproductive barrier than pollinator specificity. The aim of this study is to investigate the nature and strength of these isolation barriers which apparently halt gene flow between these two orchids that share the same pollinator. Morphological measurements, combined with observations of cross-pseudocopulations, revealed that, in sympatry, the longer caudicles of O. normanii and the smaller and differently shaped stigmatic cavity in O. chestermanii are the main factors preventing gene flow between these two sympatric species. In contrast, other pre- or post-mating barriers seem to be weak or absent, as the two species have overlapping flowering time and we were able to rear hybrid offspring from interspecific manual crosses. At the same time, genetic analysis of orchid plantlets collected at sympatric sites detected the presence of only two putative hybrid individuals. Thus, the probability of natural cross-pollination between O. normanii and O. chestermanii seems to be strongly limited by divergence in their floral morphology. For some traits, this divergence was found increased between sympatric populations.

Natural hybridization is widespread among food-deceptive orchids, whereas hybridization between deceptive and rewarding species is less common among Mediterranean species and its evolutionary consequences remain under-investigated. Here, we examine the morphological variation in floral traits, pollination success and demographic dynamics of natural hybrids between the widespread nectar-rewarding Anacamptis fragrans and the Mallorca endemic, food-deceptive A. robusta. We confirmed the status of hybrids using ribosomal DNA and assessed their maternal contribution using length polymorphism in the plastid tRNALEU intron. Genetic analyses confirmed that hybridization occurred in both directions, but the hybrids were morphologically closer in floral metric characters to A. fragrans and exhibited reduced among-individual variation in floral traits. No obvious secreting papillae were present in the hybrid spur, which more closely resembled the spur of non-rewarding A. robusta, reinforcing field observations that hybrids were probably nectarless. Compared with both rewarding and deceptive parents, the hybrids were less attractive for pollinators, most likely because of the absence of significant reward and of their combination of contrasting parental floral advertisements. In spite of its low pollination success, the hybrid population is presently expanding alongside the endemic A. robusta, suggesting that it follows the demographic dynamics of the parental species.

The landscape around the Graeco-Roman town of Neapolis was reconstructed through morphostratigraphic methods and pollen analysis of the sediments filling the bay hosting the ancient harbor. This was discovered in 2004 thanks to excavations for two new lines of the Naples metro network; the harbor's sedimentary record spans the period between the late 4th century BC and the 6th century AD. The main changes occurring in the marine and terrestrial landscape surrounding the ancient town are highlighted through the reconstruction of a detailed geological cross section and four 3D palaeogeographic models. Pollen analysis suggested the presence of mixed oak woods on the slopes surrounding the town and of vegetable gardens around the harbor area. The tree crops mainly consisted of walnut, and to a lesser extent chestnut and grapevines. The horticultural varieties were dominated by Brassicaceae, most likely representing cabbage cultivation which was rather common in Roman times. Comparison with reference pollen material reinforces this hypothesis. During the 3rd century AD a drastic decrease in horticultural activity, in concurrence with an increase in wild vegetation and tree crops, suggest reduced maintenance due to a phase of abandonment. Historical data imply for the same period a phase of economic and social decline which involved the whole Empire. From the end of the 3rd century AD, the growth of a spit bar at the port entrance gave rise to the establishment of a lagoon and then to the final closure of the bay.

The Graeco-Roman harbor of Neapolis (Naples, Italy), chronologically constrained between the late 4th century BC and the 6th century AD, offers a unique sight on relationship between past and present into the history of the marine biodiversity. In fact, the digs expose fossil leaf of Posidonia oceanica with epiphytic communities of microorganisms. Posidonia oceanica is a seagrass endemic to theMediterraneanthat forms large meadows whose remains can persist in the sediment for thousands of years. In this communication, we report results of analyses carried out using both molecular and morphological techniques on sub-fossil leaves of P. oceanica and their associated epiphytic communities.

The diverse epidendroid orchid tribe Neottieae is characterized by multiple transitions between autotrophy and mycoheterotrophy, allogamous and autogamous mating systems, pollen released as tetrads or monads, and pollen exine tectate or semitectate. We use transmission and scanning electron microscopy on pollen of ten species of Neottieae to investigate whether the differences in pollen aggregation and exine micromorphology and ultrastructure reflect phylogenetic relationships, or whether this variation is subject to ecological constraints. Our results showed that differences in exine micromorphology are mostly concordant with phylogenetic relationships in Neottieae, i.e. an ascending tendency of pollen ornamentation from tectate (Cephalanthera) to semitectate (e.g. Neottia). In contrast, pollen aggregation, when plotted on the most recent phylogeny, shows repeated transitions between monads and tetrads that could be related to ecological constraints. Tetrads are present in species that are nectar rewarding, whereas monads are common in deceptive species. Cephalanthera is characterized by recalcitrant pollen, including the frequent occurrence of collapsed pollen. In this genus, the observed shifts from allogamous to autogamous or cleistogamous mating systems could help to reduce pollen damage caused by exposure to dry habitats. © 2013 Springer-Verlag Wien.

The evolution of the apertural type in the ANITA-grade family Nymphaeaceae, despite the importance of pollen characters for both palaeobotanical and neobotanical investigations, has not been yet totally understood. To elucidate some unclear aspects regarding the homologies of the apertural condition in basal and core Nymphaeaceae, we examined the pollen grains from five species of this family. We offer for the first time some evidence about the presence of a proper operculum in the pollen grain of Nuphar and for the ring-like status of the aperture of Nymphaea caerulea and Victoria cruziana. Our findings clarify and reinforce the hypothesis of an opercular origin of the distal part of the pollen grain in the core Nymphaeaceae and support the paraphyly of the genus Nymphaea as emerged from recent molecular studies. The diversity and specialisation of this 'basal' family is underlined even by its pollen characters. © 2013 Copyright Collegium Palynologicum Scandinavicum.

International audience; A new Early Cretaceous, late Aptian plant assemblage collected near the village of Cusano Mutri in the southern Apennines (Campania, Italy) is examined. The fossils consist mainly of impressions and compressions of sterile foliage shoots and reproductive structures of conifers, and a few angiosperm leaves. Cuticular analyses are provided. The genera Cupressinocladus, Pagiophyllum, Araucarites, Frenelopsis and Montsechia are documented. The occurrence of Montsechia vidalii outside of Spain is recorded for the first time. A description of a new cheirolepidiacean species, Frenelopsis cusanensis is supplied and macroscopical and cuticular characters as seen under light and scanning electron microscopes are given. Xeromorphic features displayed by almost all taxa suggest semi-arid or arid conditions in a subtropical or tropical climate. The floral assemblage displays a strong affinity with the Euro-Sinian Province of the Northern Hemisphere, which is confirmed by the absence of typical Gondwanan representatives. The discovery of this new late Aptian flora in the Apenninic Carbonate Platform domain and its palaeoecological significance provide new insights into the relationships between the platform and the mainland within the Early Cretaceous Tethyan realm

A single specimen of a new fossil angiosperm, Sagaria cilentana gen. et sp. nov., has been recovered from limestones of the “plattenkalk” of the Middle Albian at Monti Alburni, near Petina, Campania, Italy. Associated fossils include Pagiophyllum sp., Podozamites sp. and Zamites sp. The angiosperm has a main axis approximately 8 cm long with three attached leaves and a distal cyme bearing three fructifications. The fructifications display divided distal tips indicating three - four lobes. Four cm from the base, underneath the main axis, there is a lobed structure, presumably a leaf. An unattached leaf near the specimen is in a position that suggests that it comes from the same plant. The leaf has an elongate petiole, obtuse base and on the right side of the lamina are three lobes. Affinities are uncertain but show similarities in overall morphology to basal eudicots, especially Ranunculaceae.

An examination has been carried out of the floral assemblage from the lower–middle Aptian locality of Profeti village, near Caserta, Campania, Southern Italy. The assemblage consists of vegetative and reproductive remains belonging to conifers and to isolated angiosperm leaves. The genera Brachyphyllum, Araucarites, Nageiopsis, Frenelopsis, and Cupressinocladus? are documented. Macroscopical and cuticular analyses with light and scanning electron microscopes enable the description of a new cheirolepidiacean species: Frenelopsis profetiensis. The assemblage shows the classical features of xeromorphy. Sedimentological analysis together with macroscopical and cuticular features of the studied samples, suggests a subtropical climate, probably under semi-arid or arid conditions. The floristic composition shows close affinities with other coeval Tethyan communities, but no similarity with the Gondwanan flora.