Heat and hypoxia give a global invader, <Emphasis Type="Italic">Gambusia holbrooki,</Emphasis> the edge over a threatened endemic fish on Australian floodplains

Deciphering the mechanisms by which climate change interacts with invasive species to affect biodiversity is a major challenge of global change biology. We conducted experiments to determine whether the global invader, Gambusia holbrooki, was more resistant to high water temperature (heat) and low dissolved oxygen (hypoxia) than a threatened native fish, Nannoperca australis. Metabolic experiments conducted at 25 and 29 °C showed that G. holbrooki had at least four times the capacity for metabolic depression during hypoxia than N. australis. An increase in environmental temperature from 25 to 29 °C had no significant impact on the critical oxygen tension, P _crit, of G. holbrooki, but significantly and strongly increased P _crit of N. australis. Gambusia holbrooki also had a lower Q ₁₀ of standard metabolic rate than N. australis. Our results indicate that G. holbrooki have physiological traits conferring greater resistance to hypoxia than N. australis, and as temperature increases, the resistance of N. australis to hypoxia was more eroded than that of G. holbrooki. Intensive monitoring of the temperature and dissolved oxygen dynamics of wetlands showed that contemporary heat waves are already causing conditions that might give G. holbrooki the edge over N. australis on Australian floodplains. Our study adds weight to recent anecdotal reports of drought and heat waves causing localised extinction of N. australis, but the proliferation of G. holbrooki.     

Statistical techniques for modeling of <Emphasis Type="Italic">Corylus</Emphasis>, <Emphasis Type="Italic">Alnus</Emphasis>, and <Emphasis Type="Italic">Betula</Emphasis> pollen concentration in the air

Prediction of allergic pollen concentration is one of the most important goals of aerobiology. Past studies have used a broad range of modeling techniques; however, the results cannot be directly compared owing to the use of different datasets, validation methods, and evaluation metrics. The main aim of this study was to compare nine statistical modeling techniques using the same dataset. An additional goal was to assess the importance of predictors for the best model. Aerobiological data for Corylus, Alnus, and Betula pollen counts were obtained from nine cities in Poland and covered between five and 16 years of measurements. Meteorological data from the AGRI4CAST project were used as a predictor variables. The results of 243 final models (3 taxa \(\times\)  9 cities \(\times\) 9 techniques) were validated using a repeated k-fold cross-validation and compared using relative and absolute performance statistics. Afterward, the variable importance of predictors in the best models was calculated and compared. Simple models performed poorly. On the other hand, regression trees and rule-based models proved to be the most accurate for all of the taxa. Cumulative growing degree days proved to be the single most important predictor variable in the random forest models of Corylus, Alnus, and Betula. Finally, the study suggested potential improvements in aerobiological modeling, such as the application of robust cross-validation techniques and the use of gridded variables.     

Freshwater fish diversity in Algeria with emphasis on alien species

Little is known about freshwater fish diversity in Algeria, especially after the broad national program of introduction of exotic species applied for over 20 years. This paper is an attempt to describe the current situation emphasizing the characteristics of the various introductions of non-autochthonous species, their current status and their possible impacts. The freshwater fish fauna of Algeria is composed of 48 species belonging to 15 families. Twenty-one species are autochthonous, of which, three are endemic (Haplochromis desfontainii, Aphanius saourensis, Aphanius apodus), two are endangered (H. desfontainii, Aphanius iberus), and one is critically endangered (Anguilla anguilla). Twenty-seven species were introduced, of which, 18 never became established and 9 are established. Four species are reported for the first time: Abramis brama, Aspius aspius, Carassius carassius, Perca fluviatilis. Since 1860, 303 introduction events have been recorded at almost 107 different sites in Algeria. The number of introduction events per site was between 1 and 10. Most of the introduced fish are found in Oubéïra Lake (seven species). Aquaculture development was the main reason for fish introductions (37.0%). The five most often introduced species were Cyprinus carpio (86 records), Hypophthalmichthys molitrix (65 records), Aristichthys nobilis (51 records), Oreochromis niloticus niloticus (33 records), and Ctenopharyngodon idella (18 records). Since the adverse effects of introduced fish are risky and demonstrated in several countries, the adoption of the precautionary principle is recommended when new introductions are planned. It is important, therefore, to adopt regulations and procedures which will minimize the risks arising from introductions.     

Double-check: validation of diagnostic statistics for PLS-DA models in metabolomics studies

Partial Least Squares-Discriminant Analysis (PLS-DA) is a PLS regression method with a special binary ‘dummy’ y-variable and it is commonly used for classification purposes and biomarker selection in metabolomics studies. Several statistical approaches are currently in use to validate outcomes of PLS-DA analyses e.g. double cross validation procedures or permutation testing. However, there is a great inconsistency in the optimization and the assessment of performance of PLS-DA models due to many different diagnostic statistics currently employed in metabolomics data analyses. In this paper, properties of four diagnostic statistics of PLS-DA, namely the number of misclassifications (NMC), the Area Under the Receiver Operating Characteristic (AUROC), Q ² and Discriminant Q ² (DQ ²) are discussed. All four diagnostic statistics are used in the optimization and the performance assessment of PLS-DA models of three different-size metabolomics data sets obtained with two different types of analytical platforms and with different levels of known differences between two groups: control and case groups. Statistical significance of obtained PLS-DA models was evaluated with permutation testing. PLS-DA models obtained with NMC and AUROC are more powerful in detecting very small differences between groups than models obtained with Q ² and Discriminant Q ² (DQ ²). Reproducibility of obtained PLS-DA models outcomes, models complexity and permutation test distributions are also investigated to explain this phenomenon. DQ ² and Q ² (in contrary to NMC and AUROC) prefer PLS-DA models with lower complexity and require higher number of permutation tests and submodels to accurately estimate statistical significance of the model performance. NMC and AUROC seem more efficient and more reliable diagnostic statistics and should be recommended in two group discrimination metabolomic studies.     

Crown exposure to light and tree allometry of 11 tree species in a snowy cool-temperate forest in Japan

Crown exposure to light (CE) and tree allometry were investigated for 11 species in a snowy cool-temperate secondary forest dominated by Fagus crenata and Betula ermanii in Japan. The 11 species differentiated horizontal and vertical light gradients for regeneration. CE was highly variable across species in small trees, but variation in CE decreased with increasing height. The 11 species were classified into three patterns of height-dependent change in CE in comparison to community-level trends, and rank reversal of CE with increasing height was not apparent. Allometric relationships between trunk diameter (D) and height (H) and between D and trunk length (L) differed little between trees of high and low CE within species. In contrast, slopes of the allometric relationships between D and H differed across species; species with larger maximum height (H _max) were taller at a given D, as was noted in previous studies of warm-temperate and tropical forest trees. Differences in trunk angle among the species of different H _max were the main factor generating the differences in allometric relationships between D and H in this forest. Trunk angle increased with increasing height in the species of large H _max but decreased in those of small H _max. Hence, allometric relationships between D and L were not related to H _max. Since the species of small H _max grow laterally and are easily covered in snow during winter while those of large H _max grow vertically above snow cover, differences in trunk angle may reflect species mechanical properties.     

Molecular phylogenetic analysis of key <Emphasis Type="Italic">Jatropha</Emphasis> species inferred from nrDNA ITS and chloroplast (<Emphasis Type="Italic">trn</Emphasis>L-F and <Emphasis Type="Italic">rbc</Emphasis>L) sequences

The genus Jatropha (Euphorbiaceae) contains species that are of significant economic and ornamental value. However, Jatropha breeding material is rather limited due to incomplete information regarding phylogenetic relationships among germplasm resources. Phylogenetic analyses were performed based on the internal transcribed spacer of nuclear ribosomal DNA (nrDNA ITS), two chloroplast regions (trnL-F and rbcL), and the combined (ITS+trnL-F+rbcL) dataset among twenty-five specimens representing six key Jatropha species. Phylogenetic relationships of Jatropha were well resolved between subgenus Curcas and subgenus Jatropha, and demonstrated the intermediate position of section Polymorphae among sections of both subgenera. Jatropha curcas and J. integerrima demonstrated a close phylogenetic relationship. The molecular data agreed with the morphological classification that recognized J. multifida and J. podagrica in sec. Peltatae. The distinct intraspecific divergence that occurred in J. curcas could be attributed to restricted gene flow caused by geographical isolation and different ecological conditions. Phylograms produced with trnL-F and rbcL sequence data suggested slow rates of sequence divergence among Jatropha spp., while the ITS gene tree had good resolution suggesting high genetic variation of ITS among Jatropha species.     

Do biogeographic parameters matter? Plant species richness and distribution of macrophytes in relation to area and isolation of ponds in NW Polish agricultural landscape

Effects of pond size and isolation on total vascular plant species richness and number of obligate wetland species were compared. Subsequently, the potential for the presence of spatial patterns in wetland species distribution among ponds in an agricultural landscape was explored. Relationships between species richness and two main biogeographic parameters were analysed using simple and multiple linearised regression models. Spatial patterns were looked for by means of analyses carried out with the R CRAN software (join-count statistics). Simple regression analyses performed on the regional scale (n = 50) revealed the significance of the effect of pond size only (r = 0.46 for total plant species richness and r = 0.28 for wetland species richness vs. pond area). Further analyses conducted on the local scale identified the best multiple regression models in the largest pond cluster (n = 20); the models showed statistical significance of relationships between the species richness and both independent variables (r = 0.80 for total plant species richness and r = 0.70 for wetland species richness vs. pond area and isolation, including mean distance to the nearest ten ponds). Spatial analyses were performed for 26 obligate wetland species selected from 149 species recorded in all the 50 ponds. Exploratory spatial data analysis revealed the presence of significant positive spatial autocorrelation in the distribution of 8 species. In such cases, it is possible to reject the random distribution hypothesis, which justifies exploration of spatial regimes. In practice, correct spatial model specifications may have implications for predicting species occurrences under changing environmental conditions, e.g. changes in the number of ponds.     

Environmental and ecological factors influencing the spillover of the non-native kelp, <Emphasis Type="Italic">Undaria pinnatifida</Emphasis>, from marinas into natural rocky reef communities

The non-native kelp, Undaria pinnatifida, is considered one of the world’s worst invasive species. The northeast Atlantic is a hotspot of Undaria invasion, yet there is limited knowledge on its invasion dynamics. In the UK its distribution is strongly associated with artificial structures, primarily marina and harbour pontoons, with relatively few records of Undaria on natural substrates. Here, the southwest UK is used as a case region, to explicitly link Undaria distribution-abundance patterns in artificial marina habitats with those in natural rocky reef habitats. Using a mixture of in situ recording and video survey techniques, Undaria was found at all thirteen marina sites surveyed; but in only 17 of 35 rocky reef sites, all of which were in 2 of the 5 larger systems surveyed (Plymouth Sound and Torbay). The distribution-abundance patterns of Undaria at reef sites were analysed using zero-inflated models. The probability of finding Undaria on rocky reef increased with increasing proximity to marinas with high abundances of Undaria. Total propagule pressure from marinas also increased the probability of occurrence, and was positively related to Undaria abundance and cover at reef sites. Increases in the cover of native kelps, Laminaria spp., and wave exposure at reef sites were linked to a reduced probability of Undaria occurrence, and lower abundance and cover. Identifying high risk areas, natural boundaries and factors affecting the spread and abundance of non-native species in natural habitats is key to future management prioritisation. Where Undaria is confined to artificial substrates management may be deemed a low priority. However, the results of this study suggest that controlling the abundance and propagule pressure in artificial habitats may limit, to some extent, the spillover of Undaria into natural rocky reef habitats, where it has the potential to interact with and influence native communities.     

Fish species composition,sex ratio and growth parameters in Saghamo Lake (Southern Georgia)

We provide a first investigation of fish species composition, sex ratios, age, length-weight relationships and growth models in Saghamo Lake located in Javakheti highland (Georgia). In total 713 specimens belonging to 8 species were collected included non-native Coregonus albula, Carassius gibelio and native Alburnoides bipunctatus, Squalius cephalus, Capoeta capoeta, Romanogobio persus, Salmo cf. caspius and Barbus lacerta, among which later two were recorded for the first time in the lake. In overall, relative abundances of all species is low while some species may not be presented with viable populations. Deviation from expected sex ratio, growth at age and age structure indicates severe anthropogenic pressure as a potential driver of fish community degradation in the lake.     

Molecular taxonomy and morphological characterization reveal new species and new host records of <Emphasis Type="Italic">Torula</Emphasis> species (Torulaceae,Pleosporales)

Four new species and two new host records of Torula (Torulaceae, Pleosporales) are described and illustrated from herbaceous litter collected in Italy and Thailand. The new species possess colony, conidiophore and conidial characteristics that fit within the generic concept of Torula. Detailed morphological observations clearly demarcate four of these from extant species and are hence described as new (Torula chiangmaiensis sp. nov., Torula pluriseptata sp. nov., Torula chromolaenae sp. nov., Torula mackenziei sp. nov.). Details of asexual morphs are described, and justifications for establishing these new species are provided. The nuclear are sequenced ribosomal RNA genes as well as protein coding genes to infer phylogenetic relationships and discuss phylogenetic affinities with morphologically similar species. Our morphological distinction is further supported by phylogenetic discrimination. In particular, phylogenies depict a close relationship of Torula chiangmaiensis and T. pluriseptata to T. hollandica, while T. chromolaenae and T. mackenziei constitute an independent phylogenetic lineage basal to T. herbarum and T. ficus. Torula ficus and T. masonii are also described and their phylogeny investigated as new host records from Bidens pilosa and Iris germanica, respectively.     

A Genetic Analysis of Mortality in Pigs

An analysis of mortality is undertaken in two breeds of pigs: Danish Landrace and Yorkshire. Zero-inflated and standard versions of hierarchical Poisson, binomial, and negative binomial Bayesian models were fitted using Markov chain Monte Carlo (MCMC). The objectives of the study were to investigate whether there is support for genetic variation for mortality and to study the quality of fit and predictive properties of the various models. In both breeds, the model that provided the best fit to the data was the standard binomial hierarchical model. The model that performed best in terms of the ability to predict the distribution of stillbirths was the hierarchical zero-inflated negative binomial model. The best fit of the binomial hierarchical model and of the zero-inflated hierarchical negative binomial model was obtained when genetic variation was included as a parameter. For the hierarchical binomial model, the estimate of the posterior mean of the additive genetic variance (posterior standard deviation in brackets) at the level of the logit of the probability of a stillbirth was 0.173(0.039) in Landrace and 0.202(0.048) in Yorkshire. The implications of these results from a breeding perspective are briefly discussed.LITTER size has been under selection in the Danish pig breeding program since the early 1990s and this resulted in considerable increase in total number born and also in the proportion of stillborn piglets (Sorensen et al. 2000; Su et al. 2007). A number of studies have reported genetic variation for mortality with heritabilities ranging from 0.03 to 0.12. These studies have either assumed normality of the sampling model for mortality (e.g., van Arendonk et al. 1996) or based inferences on a variety of threshold models (e.g., Roehe and Kalm 2000; Arango et al. 2006), and critical investigations of the quality of fit of the models used were not reported.Mortality data, regarded as a trait of the mother, show typically a large proportion of zeros (many litters do not have stillborn piglets). Formal genetic analyses of mortality in pigs accounting for this feature of the data are not available in the literature and this article attempts to fill this gap. The focus here is to study the quality of fit and predictive ability of a number of models and to investigate whether they provide statistical evidence for genetic variation for mortality. The statistical genetic analysis involves fitting various hierarchical models involving three discrete distributions: the Poisson, the binomial, and the negative binomial.The statistical analysis of counts based on discrete parametric distributions has a long and rich history (Johnson and Kotz 1969). In the case of unbounded counts, Poisson regression models are standard, whereas for bounded counts, when the response can be viewed as the number of successes out of a fixed number of trials, regression models based on the binomial distribution are often used (Hall 2000). A restriction of the Poisson model is that it imposes equality of mean and variance. Typically the distribution of counts is overdispersed. In the case of the binomial model the only free parameter is the probability of success, which results in a functional relationship between the mean and the variance. Several possible alternatives have been suggested to obtain more flexible models. For example, the negative binomial distribution has two parameters and allows the mean and variance to be fitted separately (Lawless 1987). An application of the negative binomial model in animal breeding can be found in Tempelman and Gianola (1996, 1999). In the same spirit, a robust alternative to the binomial model is the beta-binomial, which is a mixture of binomials where the unequal probabilities of success vary according to a beta-distribution. In general, hierarchical specifications are needed to explain extra variation that is not accounted for by the sampling model of the data. These involve assigning a distribution to the parameters of the sampling model, directly, as in the case of the negative binomial or beta-binomial models, or indirectly, by embedding these parameters in a linear structure that includes random effects as explanatory variables.There are situations where overdispersion is partly associated with an incidence of zero counts that is greater than expected under the sampling model, as in the present study. Hurdle models (Mullahy 1986; Winkelmann 2000) and zero-inflated models are two instances of finite mixture models commonly used to account for this characteristic of the data. In the present work the excess of zeros is studied using zero-inflated models that are described in Johnson and Kotz (1969) and extended by Lambert (1992). Ridout et al. (1998) provide a review of various zero-inflated models; recent applications of zero-inflated Poisson models in animal breeding are in Rodriguez-Motta et al. (2007) and in Naya et al. (2008). Zero-inflated models assume that the population consists of two sets of observations. In the first set, which may include zeros, observations are realizations from a discrete sampling process indexed by unknown parameters (this set is often referred to as the imperfect state); observations from the second set consist only of zeros and the parameter of interest is the proportion of these individuals. This set is often referred to as the perfect state. Either or both sets of parameters may depend on covariates.This article is organized as follows. material and methods describes the data, details of the models, and their Markov chain Monte Carlo (MCMC) implementation. This is followed by a presentation of the results of the analyses and of MCMC-driven explorative tools for model comparison. The article concludes with a discussion.     

Morphological and molecular taxonomy of novel species <Emphasis Type="Italic">Pleurotheciaceae</Emphasis> from freshwater habitats in Yunnan,China

The diversity of lignicolous freshwater fungi of the Greater Mekong Subregion are currently being studied. In this paper, 18 fresh collections of Pleurotheciaceae from submerged wood in freshwater are characterized based on morphological characters and analyses of ITS, LSU, SSU and RPB2 sequence data. Six new species of Pleurotheciella (P. aquatica, P. fusiformis, P. guttulata, P. lunata, P. saprophytica, P. submersa), one new Phaeoisaria species (Ph. aquatica) and one new Pleurothecium species (Pl. aquaticum) are introduced based on their distinct morphology and evidence from molecular phylogeny. Pleurotheciella uniseptata, Phaeoisaria clematidis and Pleurothecium pulneyense are also redescribed and phylogenetic relationships assessed herein, these species are the first records for China.     

Two new species of Alcantarea (Bromeliaceae,Tillandsioideae) from Brazil

Alcantarea turgida andA. tortuosa are described and illustrated as new species from southeastern Brazil. The relationships ofA. turgida withA. extensa and withA. vinicolor and ofA. tortuosa withA. farneyi and withA. benzingii are discussed.     

Differences in neurochemical profiles of two gadid species under ocean warming and acidification

Background

Exposure to future ocean acidification scenarios may alter the behaviour of marine teleosts through interference with neuroreceptor functioning. So far, most studies investigated effects of ocean acidification on the behaviour of fish, either isolated or in combination with environmental temperature. However, only few physiological studies on this issue were conducted despite the putative neurophysiological origin of the CO₂-induced behavioural changes. Here, we present the metabolic consequences of long-term exposure to projected ocean acidification (396–548 μatm PCO₂ under control and 915–1272 μatm under treatment conditions) and parallel warming in the brain of two related fish species, polar cod (Boreogadus saida, exposed to 0 °C, 3 °C, 6 °C and 8 °C) and Atlantic cod (Gadus morhua, exposed to 3 °C, 8 °C, 12 °C and 16 °C). It has been shown that B. saida is behaviourally vulnerable to future ocean acidification scenarios, while G. morhua demonstrates behavioural resilience.

Results

We found that temperature alters brain osmolyte, amino acid, choline and neurotransmitter concentrations in both species indicating thermal responses particularly in osmoregulation and membrane structure. In B. saida, changes in amino acid and osmolyte metabolism at the highest temperature tested were also affected by CO₂, possibly emphasizing energetic limitations. We did not observe changes in neurotransmitters, energy metabolites, membrane components or osmolytes that might serve as a compensatory mechanism against CO₂ induced behavioural impairments. In contrast to B. saida, such temperature limitation was not detected in G. morhua; however, at 8 °C, CO₂ induced an increase in the levels of metabolites of the glutamate/GABA-glutamine cycle potentially indicating greater GABAergic activity in G.morhua. Further, increased availability of energy-rich substrates was detected under these conditions.

Conclusions

Our results indicate a change of GABAergic metabolism in the nervous system of Gadus morhua close to the optimum of the temperature range. Since a former study showed that juvenile G. morhua might be slightly more behaviourally resilient to CO₂ at this respective temperature, we conclude that the observed change of GABAergic metabolism could be involved in counteracting OA induced behavioural changes. This may serve as a fitness advantage of this respective species compared to B. saida in a future warmer, more acidified polar ocean.

     

Effects of Common Polymorphisms in the MTHFR and <Emphasis Type="Italic">ACE</Emphasis> Genes on Diabetic Peripheral Neuropathy Progression: a Meta-Analysis

Diabetic peripheral neuropathy (DPN) is a microvascular complication of diabetes mellitus. The aim of this meta-analysis was to evaluate the effects of methylenetetrahydrofolate reductase (MTHFR) 677 C>T and ACE I/D polymorphisms in the development of DPN. We systematically reviewed published studies on MTHFR 677 C>T and ACE I/D polymorphisms and DPN found in various types of electronic databases. Strengthening the Reporting of Observational studies in Epidemiology (STROBE) quality score systems were used to determine the quality of the articles selected for inclusion. Odds ratios (ORs) and its corresponding 95 % confidence interval (95 % CI) were calculated. We used STATA statistical software (version 12.0, Stata Corporation, College Station, TX, USA) to deal with statistical data. Our results indicated an association of ACE D>I mutation (OR?=?1.43, 95 % CI 1.12–1.83, P?=?0.004) and MTHFR 677 C>T mutation (OR?=?1.43, 95 % CI 1.08–1.90, P?=?0.014) with DPN under the allele model, and similar results were also found under the dominant model (all P?<?0.05). Subgroup analysis by country indicated that the MTHFR 677 C>T polymorphism may be the main risk factor for DPN in Turkey under four genetic models. ACE D>I mutation was correlated with DPN in Japanese and Pakistani populations in the majority of groups. The relationships of MTHFR 677 C>T and ACE I/D polymorphisms with DPN patients presented in this meta-analyses support the view that the MTHFR and ACE genes might play an important role in the development of DPN.     

How salinity stress influences the thermal time requirements of seed germination in <Emphasis Type="Italic">Silybum marianum</Emphasis> and <Emphasis Type="Italic">Calendula officinalis</Emphasis>

Salinity is a major problem of many agricultural lands that is usually associated with drought stress in arid and semi-arid regions. In this study we examine the role of salinity stress on temperature requirements of two herbaceous species and how it could be modeled to quantify alterations. We applied four non-linear regression models (segmented, beta, beta modified, and dent-like) to describe the germination rate–temperature relationships of Silybum marinum L. and Calendua officinalis L. over six constant temperatures exposed to different levels of salinity stress. Our results revealed that salinity could affect the cardinal temperatures in both plants and, as a result, it is not possible to suggest one model for all levels of salinity stress. The best model to fit data to predict cardinal temperatures of Silybum marianum and Calendula officinalis at the no-salinity condition were dent-like (AICc?=?4.03) and beta (AICc = ??2.30), respectively. Knowing the thermal time constant (f_o) value helps us predict the minimum number of hours required for completion of germination at the optimal temperature. All models in this study were estimated higher f_o due to higher salinity stress in both Silybum marianum and Calendula officinalis seeds. The highest estimated f_o for Silybum marianum (91.5?±?59.6) and Calendula officinalis (178.9?±?26.5) was obtained from the results of germination rate prediction using a dent-like model at 200 mM salinity.     

Karyotypic study of five Lutjanid species using conventional and Ag-NORs banding techniques

The first cytogenetic comparisons of five snapper species from Thailand were presented here. Renal cell samples were taken from blacktail snapper (Lutjanus fulvus), five lined snapper (L. quinquelineatus), dory snapper (L. fulviflamma), brownstripe red snapper (L. vitta), and mangrove red snapper (L. argentimaculatus). The mitotic chromosome preparation was prepared directly from kidney cells. Conventional staining and Ag-NOR banding techniques were applied to stain the chromosomes. The results exhibited that all five snapper species have the diploid chromosome numbers of 2n = 48 and the fundamental numbers (NF) of 48. The presences of large, medium, and small telocentric chromosomes were 22-24-2, 24-20-4, 36-10-2, 28-16-4 and 36-10-2, respectively. The Ag- NORs banding technique provides the pair of nucleolar organizer regions (NORs) at subcentromeric region of the long arm of the respective telocentric chromosome pairs 9, 1, 3, 4 and 9. Their karyotype formulas is as follows: L. fulvus (2n = 48): L ₂₂ ^t + M ₂₄ ^t + S ₂ ^t , L. quinquelineatus (2n = 48): L ₂₄ ^t + M ₂₀ ^t + S ₄ ^t , L. fulviflamma (2n = 48): Lt36 + Mt10 + St2, L. vitta (2n = 48): L ₂₈ ^t + M ₁₆ ^t + S ₄ ^t , and L. argentimaculatus (2n = 48): L ₃₆ ^t + M ₁₀ ^t + S ₂ ^t .     

Identification of birch pollen species using FTIR spectroscopy

In this study, the morphology and chemical composition of pollen grains of six birch species (Betula utilis Doorenbos, B. dahurica, B. maximowicziana, B. pendula, B. pubescens and B. humilis) were examined to verify which of these features allow distinguishing them in a more unambiguous way. For this purpose, scanning electron microscopy and light microscopy, as well as Fourier transform infrared (FTIR) spectroscopy and curve-fitting analysis of amide I profile, were performed. The microscopy images show that the pollen grains of B. pubescens, B. pendula and B. humilis are similar in diameter and significantly smaller than those of others species, with the largest diameter observed for B. utilis Doorenbos. However, the results obtained from FTIR spectroscopy indicate that the chemical compositions of B. pubescens and B. pendula are similar, but B. humilis is outlaying. Summarizing, it is not possible to unambiguously state, which feature or which technique is the best for differentiating between the six chosen birch species. However, the study showed that both techniques have potential for identification of birch pollen species.     

Anatomical features of species of Cyperaceae from northeastern Brazil

Seventy-three species from 17 genera of Cyperaceae were studied with the aim of identifying and confirming those species with Kranz anatomy. Among the species studied, 36 exhibited Kranz anatomy; 37 did not. Of the four types of Kranz anatomy recognized in Cyperaceae, three were encountered: the chlorocyperoid type in the genera Cyperus, Kyllinga, Lipocarpha, Pycreus, and Remirea; the fimbristyloid type in Abildgaardia, Bulbostylis, and Fimbristylis; and the rhynchosporoid type in Rhynchospora. Non-Kranz anatomy was confirmed in species of the following genera: Becquerelia, Calyptrocarya, Cyperus, Diplacrum, Eleocharis, Fuirena, Hypolytrum, Pleurostachys, Rhynchospora, and Scleria. The anatomical data obtained corroborate earlier studies of species of Cyperaceae as to the presence of Kranz anatomy and the anatomical types in several species and the “Kranzkette” pattern in Cyperus ligularis and Cyperus pohlli.