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In the present study epiphytic bryophytes were employed as a model system in an integrated way both as bio-indicators at species, population and community levels and as bioaccumulators of airborne trace elements. Twenty sites with Quercus ilex trees were chosen in a Mediterranean area both in urban and natural locations, with an altitude ranging from 0 to about 500 m a.s.l., in coastal and inland areas (Campania, Italy). Data on the presence of species, cover values and phenology were recorded for each site and the Index of Atmospheric Purity (IAP) was calculated. The data matrix of frequency/cover x species was analysed by multivariate methods. Data obtained clearly show that in urban sites the number of species and IAP values are lower, and that acrocarpous mosses and vegetative reproduction occur more frequently. Contents of trace elements (Al, As, Cd, Co, Cr, Cu, Fe, Mn, Mo, Ni, Pb, Ti, V, Zn) were measured in four species and concentrations were normalised to the soil pattern by calculating the Enrichment Factor (EF). The results show the large contribution of resuspended soil particles to the chemical composition of the analysed bryophytes. All the examined species were enriched in Cd, Cu and Zn, and in some cases showed high EF for Pb. The differences among epiphytic bryophyte vegetation are discussed in order to evaluate suspected alterations due to human impact and/or environmental change.

This work aims to extend our knowledge on the antibacterial and antifungal activity of the liverwort, Lunularia cruciata (Bryophyta). We evaluated the action of its acetone extract against 13 bacterial and 2 fungal strains. On pharmacological screening, substantial antibacterial activities were observed for the acetone extract of the mature gametophyte of L. cruciata while antifungal activity was not observed on the strains tested. Adult thalli of L. cruciata, collected in the Botanical Gardens of Naples, underwent extraction with acetone. Inhibition of bacterial growth was compared with that of Na-cefotaxime, benzyl penicillin, and tetracycline, while the antifungal activity was compared with that of griseofulvin. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined for the extract showing exclusively bacteriostatic activity.

An acetone extract of the moss Pleurochaete squarrosa was tested against eleven bacterial strains, some of which are pathogenous for man. The extract was active on some Gram-negative strains. Antibacterial activity of the extract, expressed as MICs, was compared with three reference antibiotics. Acute toxicity assay was performed in Balb C mice. (C) 1998 Elsevier Science B.V./International Society of Chemotherapy. All rights reserved.

Detached leaves of Pleurochaete squarrosa in culture give rise to filaments and buds. In a nutrient-free medium and in the wild these filaments have features comparable to the rhizoids, while in the presence of nutrients they resemble chloronemata and caulonemata. The protonemal apparatus in Pleurochaete squarrosa originates exclusively from the cells between the lamina and the midrib, while the buds grow both directly from these cells or from the protonemata. The formation of filaments and buds from leaves still attached to the stem is slower and less frequent, probably as a consequence of morphogenetic control by the apex. Asexual propagation in Pleurochaete squarrosa is discussed in relation to the experimental data and field observations. Regeneration from detached leaves is the major form of regeneration in this moss.

Protonemata of Funaria hygrometrica grown in artificial media containing different lead concentrations grow more slowly than controls and show a disturbance of polar growth, changed arrangement of chloroplasts, alterations of nucleus and septa position. Morphological effects are dose-dependent. At the lowest lead concentration (10-6 M), only a delay in development was observed, but no cellular alterations, At 10-5 M Pb nuclear migration, cellular shape, size and position of plastids, were altered and a variety of aberrant forms were present. At 10-4 M, besides these alterations, a drastic reduction of the protonemal system, high vacuolation and the growth of protonemal filaments from leaves were evident. The highest concentration, (10-3 M), caused death. Patterns of protonemal development and cellular arrangement in lead-treated samples showed similarities as well as differences, if compared to alterations induced by colchicine. Indirect immunofluorescence demonstrated a correlation between lead concentration and alteration of cytoskeletal organization (alterations similar to those induced by colchicine). Hypotheses are raised to account for effects of lead on microtubule structure, arrangement and cytoplasm organization.

In this paper different water-holding and transport adaptations to face the uneven and intermittent distribution of water in the ectohydric moss Tortula ruralis are referred to.The external conduction of water is operated by different and efficient systems (spaces between adjacent shoots, between leaves, leaves and stems, leaves and rhizoids, life form, etc.) which facilitate absorption and transport of solutions.Also epi-organ capillary systems (bases and revoluted margin of leaves, a groove, a close network of capillary channels determined by the papillae), intra-organ capillary systems (hyalocysts) and certain amount of internal conduction (conducting parenchyma, stereo- ma) co-operante to absorb and distribute water to the whole gametophyte.In addition, some adaptations to xerophytism and heliophytism (life form, disposition of phylloids, hair-points) are discussed. © Taylor & Francis Group, LLC.

Optical and SEM observation on the thallus of Lunularia cruciata show the presence of a hyaline parenchyma consisting of polyedric, slightly elongated cells with secondary wall thickenings mostly parallel. After removal of cytoplasmic content by mean of Triton-X-100, SEM observations show that the walls of the reticulate cells constituting the hyaline parenchyma have, between wall thickenings, large primary pit fields with numerous plasmodesmata derived pores on the unthickened areas of the walls. By contrast, the parenchymatous cells constituting the nerve have plasmodesmata derived pores grouped in small sparse fields, especially on the transverse of oblique walls. The authors suggest that the reticulate cells play a role in water holding capacity and lateral distribution, by symplastic and apoplastic conduction, of solutions carried by the midrib. A possible uniform pattern for water transport and distribution in all Marchantiales showing a similar histological organization of thallus is also ...

Detached leaves of Pleurochaete squarrosa in culture give rise to filaments and buds. In a nutrient-free medium and in the wild these filaments have features comparable to the rhizoids, while in the presence of nutrients they resemble chloronemata and caulonemata. The protonemal apparatus in Pleurochaete squarrosa originates exclusively from the cells between the lamina and the midrib, while the buds grow both directly from these cells or from the protonemata. The formation of filaments and buds from leaves still attached to the stem is slower and less frequent, probably as a consequence of morphogenetic control by the apex. Asexual propagation in Pleurochaete squarrosa is discussed in relation to the experimental data and field observations. Regeneration from detached leaves is the major form of regeneration in this moss.