Significance of flavonoid levels in a phenetic taxonomy of the genus Betula

ABSTRACT

Leaves of 8 species of Betula (Operational Taxonomic Units, OTU) were collected during different periods of the growing season. After drying, total flavonoid (TF) and quercetin (Q) contents were determined. Finally the TF/Q ratio was calculated. All the values describing taxonomical features were used to obtain the data matrix. Numerical analysis of the values was performed in the convention of phenetic taxonomy, yielding a set of dendrograms. The objects representing the same species (especially Betula verrucosa) were grouped in one cluster indicating that the overall similarity of birches based on flavonoid contents was not affected by environmental conditions. The results of this study support, in part, the classification proposed by PAWLOWSKA (1983) based on biochemical characteristics and chromosome number.     

Microbiological,biochemical, physicochemical surface properties and biofilm forming ability of Brettanomyces bruxellensis

Purpose

Brettanomyces bruxellensis is a serious source of concern for winemakers. The production of volatile phenols by the yeast species confers to wine unpleasant sensory characteristics which are unacceptable by the consumers and inevitably provoke economic loss for the wine industry. This ubiquitous yeast is able to adapt to all winemaking steps and to withstand various environmental conditions. Moreover, the ability of B. bruxellensis to adhere and colonize inert materials can be the cause of the yeast persistence in the cellars and thus recurrent wine spoilage. We therefore investigated the surface properties, biofilm formation capacity, and the factors which may affect the attachment of the yeast cells to surfaces with eight strains representative of the genetic diversity of the species.

Methods

The eight strains of B. bruxellensis were isolated from different geographical and industrial fermentation origins. The cells were grown in synthetic YPD medium containing 1% (w/v) yeast extract (Difco Laboratories, Detroit), 2% (w/v) bacto peptone (Difco), and 1% (w/v) glucose. Surface physicochemical properties as electrophoretic mobility and adhesion to hydrocarbon of the cells were studied. The ability of the strains to form biofilm was quantified using a colorimetric microtiter 96-well polystyrene plate. Biochemical characteristics were examined by colorimetric methods as well as by chemical analysis.

Result

Our results show that the biofilm formation ability is strain-dependent and suggest a possible link between the physicochemical properties of the studied strains and their corresponding genetic group.

Conclusion

The capacity to detect and identify the strains of the spoilage yeast based on their biofilm formation abilities may help to develop more efficient cleaning procedures and preventing methods.

     

Phylogenetic relationships between Leymus (Poaceae,Triticeae) and related diploid Triticeae species based on isozyme and genome-specific random amplified polymorphic DNA (RAPD) markers

Abstract

To investigate the phylogenetic relationships between Leymus and related diploid species of the Triticeae tribe, the esterase isozyme (EST), superoxide dismutase (SOD) isozymes, and genome-specific random amplified polymorphic DNA (RAPD) markers were used to analyze for 14 Leymus species, together with two Psathyrostachys species (Ns), three Pseudoroegneria species (St), two Hordeum species (H), Lophopyrum elongatum (E^e), Australopyrum retrofractum (W), and Agropyron cristatum (P). The data were used to construct dendrograms by means of UPGMA in the NTSYS-pc computer program. The results suggested that (1) isozyme analysis can be used in the systematic studies of these perennial Triticeae; (2) there is a close relationship between Leymus, Psathyrostachys juncea, three Pseudoroegneria species, and Lophopyrum elongatum; (3) the Ns genome-specific RAPD marker was present in all 14 polyploid species of Leymus, while the E^e and P genome-specific RAPD markers were absent in 14 polyploid species of Leymus; the St, W and H genome-specific RAPD markers were present in some species of Leymus; (4) Leymus species have multiple origins, and different Leymus species derived their genomes from different donors.     

Cytosolic ascorbate peroxidase in Gymnosperms

ABSTRACT

Sixteen species of Gymnosperms have been screened for cytosolic ascorbate peroxidase by means of native polyacrylamide gel electrophoresis. This analysis shows that a single form of the enzyme is the most common situation. The enzyme reveals a similar electrophoretic mobility in species belonging to the same genus and sometimes to different genera. In some Pinaceae, two bands of activity were observed. The presence in the archaic spermatophyte Ginkgo biloba, as well as in the more advanced monocotyledons, of three isoforms of ascorbate peroxidase, might suggest that three different cytosolic ascorbate peroxidase genes were already present in this archaic species.     

Electrophoretic protein patterns of three species ofPhytophthora associated with black pod disease of cocoa (Theobroma cacao L.)

When electrophoretic profiles of native proteins from vegetative mycelia ofPhytophthora palmivora, Phytophthora capsici and Phytophthora citrophthora causing black pod disease of cocoa in India were compared on a single Polyacrylamide gel, the isolates of same species were readily distinguished both qualitatively by visual similarity in banding patterns and quantitatively by calculating similarity coefficients. Similarity coefficients were generally much higher between isolates within a species than between isolates of different species. The dendrograms obtained after unweighted pair grouping with arithmetic averaging cluster analysis, revealed that all the isolates ofPhytophthora capsici were highly homogenous and formed a single cluster. The isolates ofPhytophthora citrophthora were resolved into two electrophoretic types which were clustered into two distinct sub groups.Phytophthora palmivora formed a separate group. Thus, the results reveal that polyacrylamide gel electrophoresis can be used successfully in distinguishing species and sub groups within a species ofPhytophthora encountered on cocoa. CPCRl contribution No. 914.     

Stand- and plot-level changes in a boreal forest understory community following wildfire

Background: Boreal forest understory plant communities are known to be resilient to fire – the species composition of stands after a fire is quite similar to the pre-fire composition. However, we know little about recovery of individual plants within particular locations in forest stands (i.e. plot-level changes) since we usually do not have pre-fire data for plots.

Aims: We wanted to determine whether species recruited into the same or different locations in a Pinus banksiana stand that experienced a severe wildfire.

Methods: We used pre-existing permanent plots to evaluate the cover of understory after an unplanned wildfire.

Results: Across the entire stand nine of 47 species showed a significant change in cover. The largest change in a plant functional group was in the mosses, with all species present before fire being eliminated. There was no change in species diversity or total cover. At the plot level, species composition showed a much greater change. An average of 47% of the species present in a plot before the fire were absent in the same plot after the fire, and the total species turnover in plots was 88% of the species present before the fire. The plots showed a similar shift in species composition.

Conclusions: These results confirm that boreal forest communities show a high degree of resilience to fire, but within a forest stand species will be found in different locations following fire, potentially exposing them to a different set of biotic and abiotic conditions in these new locations.     

Some morphometric,anatomical and biochemical characteristics of fruits and seeds of Onobrychis spp. in Italy

ABSTRACT

The fruits, seed coats and seed storage proteins of Onobrychis arenaria, O. montana, O. viciifolia, O. alba, O. supina and O. caput-galli were studied to examine the variability between and within species. The morphometric characteristics of the fruit had a high intraspecific variability which often exceeded that between species. Only the fruit of O. caput-galli had values for length, width, thickness and number of thorns which were almost always higher than those of the other species. The anatomical characteristics of the seed coats were extremely variable. The highest values of seed coat thickness were recorded in the diploid species. The palisade-like layer (or Malpighian cells) in O. caput-galli differed in size and morphology from that of the other species. The electrophoretic analysis revealed that the number and position of storage proteins varied between and within species.     

Report of the Alpine Section

Background: Under climate-change scenarios, rock outcrops, by providing microclimatically diverse habitats, different from those of surrounding zonal vegetation matrix, may serve as climatic refugia and thereby facilitate the persistence of specialist species.

Aim: We tested whether rock outcrops of southern temperate latitudes could act as local refugia for a cold-adapted flora in the face of global warming.

Methods: We related species composition of 50 outcrops and that of their surrounding vegetation to climatic data at local and regional scales to establish whether species distributions reflected differences that could indicate the existence of climatic refugia.

Results: While at a regional scale, species composition of the outcrops across the study area was related to mean annual precipitation and mean annual maximum temperature, locally, southern faces of outcrops had different species and lower maximum temperatures than insolated north faces and surrounding vegetation plots.

Conclusions: South faces of outcrops by providing cool microhabitats, and currently harbouring species not found in the surrounding zonal vegetation matrix, could serve as local refugia for heat-intolerant plants and other microthermic organism. The degree of ‘stability’ of these refugia will depend on the degree of future change in climate. Therefore, it is important to plan protected area networks that maximise local environmental heterogeneity, including the protection of rock outcrops both as refugia for cold-adapted species and as potential stepping stones that would allow dispersal of these species between supportive environments through unfavourable ones.     

Report of the Annual Conference of the Cryptogamic Section, 1948

Background: Trait-based assembly rules are a powerful tool in community ecology, used to explore the pattern and process of community structure (richness and composition).

Aims: A preliminary test for the utility of trait-based assembly rules in explaining cryptogamic epiphyte communities (lichens and bryophytes).

Methods: We sampled epiphytes from three different tree species (aspen, birch and pine), and from trees of contrasting age. The community composition of epiphyte species (taxon analysis) and functional groups (trait analysis) was summarised using multivariate ordination (nonmetric multidimensional scaling, NMDS).

Results: Ordination documented a widely observed pattern in which different tree species have taxonomically different epiphyte communities. However, NMDS sample scores were correlated to tree age in the trait-based analysis, but not in the taxon analysis.

Conclusions: Our results point to the existence of a common pattern in community traits during succession (on trees of different age) when measured for epiphyte communities with contrasting taxonomic composition. This pattern is evidenced by consistent trends in lichen growth form and reproductive strategy (sexual vs. asexual).     

Floristic diversity and the richness of locally endangered plant species of semi-natural grasslands under different management practices,southern Kyushu,Japan

Background: The rapid decline of semi-natural grasslands in Japan threatens many relic and endemic plant species. There is insufficient knowledge on how the impacts of land-use changes and management of grasslands have been affecting grassland ecosystems and what conservation measures may be taken to conserve as much of the existing plant diversity as possible.

Aim: We assessed the existing management regimes for their suitability for conserving Red Data Book (RDB) species.

Methods: We conducted our study in four districts of Kushima, Kyushu, south-west Japan, with different land-use histories. We compared species richness, plant density and abundance in six grassland types: regularly burnt, regularly mown, paddy levee, roadside, landslip and wetland communities in a total of 289 1 m x 1 m quadrats, recorded in172 grassland patches. Species richness plant density and abundance were analysed with special reference to RDB species under different land use history.

Results: Species richness of grasslands did not differ across different land use histories, yet our analysis showed that the reduced area of grasslands markedly affected the density of RDB species. Grassland types differed in their ability to support RDB species: regularly burnt grasslands were the richest in RDB species and poorest in alien species, followed by regularly mown grasslands, paddy levees, landslip, wetland and roadside communities.

Conclusions: Traditional management regimes, such as regular burning or mowing of grasslands have the best potential for conserving RDB species, and thus should be part of conservation management practices of semi-natural grasslands.     

Cytosolic ascorbate peroxidase in some species of the Quercus genus

ABSTRACT

Six species of the Quercus genus (Quercus ilex L., Q. coccifera L., Q. suber L., Q. trojana Webb, Q. macrolepis Kotschy, Q. cerris L.) have been screened for cytosolic ascorbate peroxidase (APX) by means of native polyacrylamide gel electrophoresis (PAGE). A single isozyme was found in five species (Q. trojana, Q. suber, Q. cerris, Q. macrolepis and Q. coccifera), while Q. ilex shows two different APX proteins. The data showed marked similarities among Q. trojana, Q. suber, Q. cerris and Q. macrolepis with respect to the electrophoretic mobility. The validity of APX electrophoretic patterns in systematic studies is discussed.     

Natural variation of nickel,zinc and cadmium (hyper)accumulation in facultative serpentinophytes Noccaea kovatsii and N. praecox

Aims

Data on the variability of hyperaccumulation potential of the facultative serpentinophytes Noccaea kovatsii and N. praecox on different geological substrates are scarce. The aim of this study was to assess the accumulation potential of these two species from ultramafic and non-ultramafic substrates, with special emphasis on the hyperaccumulation of Ni, Zn and Cd.

Methods

Samples of plants and corresponding soils were collected from 16 sites covering a wide range of geochemistry. Elemental concentrations were determined in the roots, shoots and the rhizosphere soils. The pH, particle size distribution and content of organic matter were also determined in the soil samples.

Results

All ultramafic accessions of both species hyperaccumulated Ni with high intraspecific variability. Only one accession of N. kovatsii from a schist soil hyperaccumulated Zn, with also a high Cd accumulation. Accumulation and translocation of Ni in both species were much higher in the ultramafic accessions, whereas Zn accumulation and translocation was found in both ultramafic and non-ultramafic accessions.

Conclusions

Ni accumulation and translocation was restricted to ultramafic populations of both species, whereas it is a species-wide trait for Zn. This study provides new and comprehensive information on the natural variation of hyperaccumulation of Ni, Zn and Cd in N. kovatsii and N. praecox.

     

On Cannabis indica,Indian hemp

Background: The South Aegean Volcanic Arc (SAVA), one of the most notable geological structures of the Mediterranean Sea, is floristically well known. Nevertheless, the factors that contribute to shaping the plant species richness of the SAVA remain unclear.

Aims: To investigate the factors that affect plant species richness and identify plant diversity hotspots in the SAVA and other central Aegean islands.

Methods: We used stepwise multiple regression to test the relationship between a number of environmental factors and plant species richness in the SAVA, as well as the residuals from the species–area linear regressions of native, Greek and Cycladian endemic taxa as indicators of relative species richness.

Results: The area was confirmed to be the most powerful single explanatory variable of island species richness, while geodiversity, maximum elevation and mean annual precipitation explained a large proportion of variance for almost all the species richness measures. Anafi, Amorgos and Folegandros were found to be endemic plant diversity hotspots.

Conclusions: We have demonstrated that geodiversity is an important factor in shaping plant species diversity in the Cyclades, while mean annual precipitation, human population density and maximum elevation were significant predictors of the Greek endemics present in the Cyclades. Finally, Anafi was found to be a plant diversity hotspot in the South Aegean Sea.     

Ultrastructural study of change from free-nuclear to cellular endosperm in Ipomoea purpurea Roth and Cytinus hypocistis L.

Abstract

The process of cellularization of the endosperm was studied in Ipomoea purpurea Roth and Cytinus hypocistis L. In both the examined species normal cytochinesis, involving the formation of the phragmoplast, characterizes the change from the nuclear to cellular condition. Nevertheless, some ultrastructural aspects of the cell wall initiation seem to indicate that the modality of freely-growing walls cannot be excluded. The hypothesis of a unique method of wall initiation for the endosperm of the nuclear type, formulated by some Authors, is discussed.     

Fourteenth research symposium University of Durham 1974

Abstract

Background: Few studies analysing lichen diversity have simultaneously considered interactions among drivers that operate at different spatial and temporal scales.

Aims: The aims of this study were to evaluate the relative importance of host tree, and local, landscape and historical factors in explaining lichen diversity in managed temperate forests, and to test the potential interactions among factors acting at different spatial scales.

Methods: Thirty-five stands were selected in the ?rség region of western Hungary. Linear models and multi-model inference within an information-theory framework were used to evaluate the role of different variables on lichen species richness.

Results: Drivers at multiple spatial scales contributed to shaping lichen species richness both at the tree and plot levels. Tree-level species richness was related to both tree- and plot-level factors. With increasing relative diffuse light lichen species richness increased; this effect was stronger on the higher than on the lower part of the trunks. At the plot scale, species richness was affected by local drivers. Landscape and historical factors had no, or only a marginal, effect.

Conclusions: Lichen conservation in temperate managed forests could be improved if the complex interactions among host tree quality and availability, micro-climatic conditions, and management were taken into consideration.     

Fifteenth annual research symposium University of Glasgow, 1975

Background: All human land use (LU) affects the distribution of plant species; however, the impacts vary with the type/intensity of LU. For managing ecosystems, it is therefore essential to understand the effects of LU types on the distribution of plant species on a macroscale.

Aims: The objectives of our study were to quantify the effects of various LU types on the distribution of vascular plant species in Japan and to determine in particular the extent to which LU was an important factor for the distribution of common species.

Methods: Based on a logistic regression model and variation partitioning being applied to each plant species, we evaluated the partial deviance by six LU types, four climatic types and three topographic and geological factors for 647 plant species at 14,412 sites in Japan.

Results: The effect of LU was significant for species present at multiple sites. Of the six LU types, secondary vegetation and plantation were the most important factors determining species distribution for many species.

Conclusions: Our results suggest that distribution of the common species is largely affected by LU on macroscale. The design of LU relating to secondary vegetation and plantations will thus be important in determining changes in the vegetation composition within Japan.     

Counting birds on farmland habitats in winter

Capsule Perimeter counts underestimate the number of birds using agricultural fields.

Aims To determine the degree to which farmland birds may be undercounted on field surveys and the factors influencing this.

Methods In a study of 96 fields, birds in the field were counted during a walk of the perimeter. Afterwards transects were walked across the field to determine the number of birds missed. Additionally in a national survey we looked at the birds seen in field transects expressed as a proportion of the total seen in the transect and on perimeter counts.

Results To obtain an accurate count of birds on a field requires the use of the whole-area search methodology especially for species such as Grey Partridge Perdix perdix, Snipe Gallinago gallinago, Skylark Alauda arvensis and Meadow Pipit Anthus pratensis. However, for a large number of species, including thrushes, flocking finches and buntings, over 90% of individuals can be recorded using the much less time-consuming perimeter count method.

Conclusions Perimeter counts are likely to be reliable for most species but special efforts may be required for a few cryptic species.     

Past and present vegetation in relation to solifluction on Ben Arkle,Sutherland

Background: Forest succession in tropical pastures usually starts from woody vegetation patches. Patches may arise within the grass matrix at microsites with favourable soil conditions or through facilitation by established nurse plants.

Aims: We report the formation of woody vegetation patches in tropical pastures after investigating whether patch formation was associated with micro-scale terrain features and whether facilitation was important for patch initiation.

Methods: The study was conducted in three pasture sites in the Atlantic forest domain of Brazil. We compared soil, terrain and species abundance patterns among pairs of woody patch and open pasture plots.

Results: The effect of variation in soil physical and chemical attributes was limited. Some species were able to establish in the grass matrix and survive disturbance from grazing and fire, while other species only established in patches, under other already established trees or shrubs. Some of these species were exotics, which are commonly eliminated in restoration efforts.

Conclusions: Allowing the establishment of species capable of withstanding pasture environments, including exotics, can accelerate succession. Furthermore, the abilities to endure competition from grasses and survive fire are key features of species suitable for the initial stages of forest restoration in tropical pastures.     

Supplement to the hepatic flora of the Shetland Islands

Background: Grasslands have only a few dominants and most of the diversity consists of subdominants. Because dominants differ widely in phenology and resource use, dominants may control the recruitment and establishment of other species.

Aims: To explore the relationship between the identity of the dominant species and successional vegetation changes in grassland communities.

Methods: The compositional change over 23 years in 1900 permanent plots dominated by four grasses (Andropogon gerardii, Elymus repens, Poa pratensis and Schizachyrium scoparium) was examined within 19 old fields in Minnesota. Fields were abandoned 1–56 years before sampling. Rate of directional change and degree of compositional dissimilarity were determined.

Results: Non-natives, P. pratensis and E. repens, were associated with either no or a slow directional change. Elymus repens was associated with high dissimilarity and P. pratensis with intermediate dissimilarity. Natives, A. gerardii and S. scoparium, were associated with compositional change that followed expectations based on field age. The rate of directional change and degree of dissimilarity between sampling intervals was lower for A. gerardii relative to S. scoparium, the only species to be associated with strong directional change.

Conclusions: Dominance by non-native grass species may impede traditional successional processes and result in a community composition quite dissimilar from native prairies.     

An analysis of allozymic characters of four species of New Zealand Amalda (Gastropoda: Olividae: Ancillinae)

Abstract

This contribution reports the results of an electrophoretic analysis of four species of the molluscan genus Amalda. The results of this analysis confirm that four taxonomically defined species are also biologically distinct, that their often considerable morphological variability is a within-species phenomenon, and that a previously undescribed form of A. depressa, which is genetically and morphologically distinct, occurs in the Bay of Islands. The genetic data were analysed cladistically and the resulting phylogenetic classification supports that based on morphology.