Image analysis as a tool for quantitative phycology: a computational approach to cyanobacterial taxa identification

In the following work we discuss the application of image processing and pattern recognition to the field of quantitative phycology. We overview the area of image processing and review previously published literature pertaining to the image analysis of phycological images and, in particular, cyanobacterial image processing. We then discuss the main operations used to process images and quantify data contained within them. To demonstrate the utility of image processing to cyanobacteria classification, we present details of an image analysis system for automatically detecting and classifying several cyanobacterial taxa of Lake Biwa, Japan. Specifically, we initially target the genus Microcystis for detection and classification from among several species of Anabaena. We subsequently extend the system to classify a total of six cyanobacteria species. High-resolution microscope images containing a mix of the above species and other nontargeted objects are analyzed, and any detected objects are removed from the image for further analysis. Following image enhancement, we measure object properties and compare them to a previously compiled database of species characteristics. Classification of an object as belonging to a particular class membership (e.g., “Microcystis,”“A. smithii,”“Other,” etc.) is performed using parametric statistical methods. Leave-one-out classification results suggest a system error rate of approximately 3%. Received: September 6, 1999 / Accepted: February 6, 2000     

Airborne pollen survey of central calcutta,india, in relation to allergy

A continuous aeropalynological survey at Central Calcutta for two consecutive years (1985–1987) was done by using a Burkard Seven Day Recording Volumetric Spore Trap. A total of 65 pollen taxa was identified of which pollen of Trema orientalis showed a maximum frequency (about 68%) followed by Poaceae and Cyperaceae. A pollen calendar was prepared and seasonal periodicities were recorded. Some entomophilous pollen types (e.g., Delonix regia, Bougainvillea spectabilis) were also observed. The presence of pollen of Pinus, Podocarpus, and Alnus in the air of Calcutta is probably due to long distance transport from Eastern Himalayas where these plants grow. Routine skin tests were performed by using the antigenic extracts of 22 pollen types where grass, Catharanthus roseus, Cocos nucifera, Azadirachta indica, Carica papaya, Albizia lebbek, Shorea robusta, Eucalyptus sp., Terminalia sp., were proved to be allergenically potent.     

PALYNOLOGY AND SYSTEMATICS OF CUPHEA (LYTHRACEAE). II. POLLEN MORPHOLOGY AND INFRAGENERIC CLASSIFICATION

Present taxonomic studies in Cuphea (Lythraceae) reveal that a broad spectrum of biosystematic data is required for an understanding of evolutionary relationships among this large and complex group of species. As part of these studies pollen data have proven to be of greater pragmatic value than is frequently true for more stenopalynous taxa. A survey is made of pollen types in 160 species of Cuphea with special reference to specific taxonomic problems, and a summary presented of points at which pollen data can profitably contribute to taxonomic revision of the genus.     

Chloroplast DNA variations in sect. Cyclachaena of Iva (Asteraceae)

Much argument has been occasioned by questions having to do with generic concepts in the tribe Heliantheae, subtribe Ambrosiinae, especially involving the genus Iva. Some workers recognize five genera (e.g., Leuciva, Chorisiva, Oxytenia, Cyclachaena, and Iva s. str.), while others recognize only a single genus Iva s. 1. Although chemical, pollen ultrastructure, and other morphological data have challenged the latter concept, relationships among the segregate taxa are still unclear. The current study used cladistic analyses of chloroplast DNA variation to investigate evolutionary relationships within Iva s. l., especially within the controversial section Cyclachaena. Nuclear rDNA was also utilized to test for hybrid origin of selected taxa. The results support the dismemberment of Iva s. l. and recognition of Iva s. str., largely because Iva s. l. is shown to be paraphyletic. Most members of the section Cyclachaena were found to have relatively close interspecific relationships. Nevertheless, cpDNA data strongly support two lineages within Cyclachaena. One lineage, including I. xanthifolia, I. acerosa, I. nevadensis, and I. dealbata, has a close relationship with the genus Euphrosyne. The second lineage includes only one species, I. ambrosiaefolia, which is closely related to Dicoria. The origin of I. ambrosiaefolia was shown to be monophyletic, not involving hybridization.     

Floral resources foraged by Geotrigona argentina (Apidae,Meliponini) in the Argentine Dry Chaco forest

This study is the first contribution to knowledge of the relationships between Geotrigona argentina and the plants of the Argentine Dry Chaco forest. A total of 1260 g of honey (corresponding to 146 pots) and 763 g of pollen (63 pots) stored in four underground nests was studied. The honey pots from each nest were homogenised and the four honey samples were analysed by melissopalynological methods, whereas the pollen pots were studied individually. Both classical counts and counts affected by the volume of the pollen types were carried out. Pollen data were statistically analysed. Additional data on both protein and lipid content is also provided. A total of 39 pollen taxa were identified. Pollen collection was focused on a few pollen taxa: Prosopis, Castela coccinea, Maytenus and Capparis; these taxa, together with Ziziphus mistol and Pisonia zapallo, were also important nectar sources. The preliminary results show that pollen collection varied seasonally, being most diverse in the summer when G. argentina incorporates herbaceous plants into its diet. The pollen collection spectrum of G. argentina is similar to that of other Trigonina bees in that the main plant species collected are a few large shrubs or trees, whose flowering consists of small and clustered flowers. Pots with large amounts of monofloral loads with pollen from only a few species suggests an organised foraging behaviour that includes the recruitment of foragers, such as that observed in other eusocial bees.     

A Total Evidence Phylogeny of the Arctoidea (Carnivora: Mammalia): Relationships Among Basal Taxa

A total evidence phylogenetic analysis was performed for 14 extant and 18 fossil caniform genera using a data matrix of 5.6 kbp of concatenated sequence data from six independent loci and 80 morphological characters from the cranium and dentition. Maximum parsimony analysis recovered a single most parsimonious cladogram (MPC). The topology of the extant taxa in the MPC agreed with previous molecular phylogenies. Phylogenetic positions for fossil taxa indicate that several taxa previously described as early members of extant families (e.g., Bathygale and Plesictis) are likely stem taxa at the base of the Arctoidea. Taxa in the “Paleomustelidae” were found to be paraphyletic, but a monophyletic Oligobuninae was recovered within this set of taxa. This clade was closely related to the extant genera Gulo and Martes, therefore, nested within the extant radiation of the family Mustelidae. This analysis provides a resolution to several discrepancies between phylogenies considering either fossil taxa or extant taxa separately, and provides a framework for incorporating fossil and extant taxa into comprehensive combined evidence analyses.     

Transport of airborne pollen into the city of Thessaloniki: the effects of wind direction, speed and persistence

We examined the effect of the wind vector analyzed into its three components (direction, speed and persistence), on the circulation of pollen from different plant taxa prominent in the Thessaloniki area for a 4-year period (1996–1999). These plant taxa were Ambrosia spp., Artemisia spp., Chenopodiaceae, Corylus spp., Cupressaceae, Olea europaea, Pinaceae, Platanus spp., Poaceae, Populus spp., Quercus spp., and Urticaceae. Airborne pollen of Cupressaceae, Urticaceae, Quercus spp. and O. europaea make up approximately 70% of the total average annual pollen counts. The set of data that we worked with represented days without precipitation and time intervals during which winds blew from the same direction for at least 4 consecutive hours. We did this in order to study the effect of the different wind components independently of precipitation, and to avoid secondary effects produced by pollen resuspension phenomena. Factorial regression analysis among the summed bi-hourly pollen counts for each taxon and the values of wind speed and persistence per wind direction gave significant results in 22 cases (combinations of plant taxa and wind directions). The pollen concentrations of all taxa correlated significantly with at least one of the three wind components. In seven out of the 22 taxon-wind direction combinations, the pollen counts correlated positively with wind persistence, whereas this was the case for only two of the taxon-wind speed combinations. In seven cases, pollen counts correlated with the interaction effect of wind speed and persistence. This shows the importance of wind persistence in pollen transport, particularly when weak winds prevail for a considerable part of the year, as is the case for Thessaloniki. Medium/long-distance pollen transport was evidenced for Olea (NW, SW directions), Corylus (NW, SW), Poaceae (SW) and Populus (NW).     

Significance of palynology for phylogeny ofAnnonaceae: Experiments with removal of pollen characters

Phylogenetic analyses based on morphology placeAnaxagorea and other taxa with granular monosulcate pollen, as in otherMagnoliales, at the base ofAnnonaceae. Taxa with columellar tetrads, granular tetrads, and inaperturate monads form a derived clade. To test the systematic importance of palynology, we analyzed the data set with pollen characters removed. The result was lower resolution and a different rooting of the family, betweenUvariopsis and other groups with columellar tetrads.Anaxagorea and other monosulcates are higher in the tree, implying that granular monosulcate pollen, laminar stamens, and irregular endosperm ruminations are reversals. This rooting is highly unparsimonious when pollen characters are included, and only weakly supported over theAnaxagorea rooting when pollen is excluded. Together with preliminary molecular analyses, these experiments confirm the special value of palynology in systematics ofAnnonaceae. This paper is dedicated to emer. Univ.-Prof. DrFriedrich Ehrendorfer on the occasion of his 70th birthday     

Pollination ecology ofOxalis violacea (Oxalidaceae) following a controlled grass fire

Vernal grass fires may encourage profuse flowering in clonal, colonies ofOxalis violacea. Long-styled colonies appear to be more floriferous than short-styled colonies and set a greater number of capsules. Individual flowers of both morphs live one or two days, change position on their respective pedicels and advertise nectar concealed at the base of the floral throat. AlthoughDiptera, Hymenoptera, andLepidoptera forage for nectar, bees (Andrenidae,Anthophoridae, Halictidae, andMegachilidae) probably make the only effective pollen transfers between the two morphs. Both male and female bees may transport pollen of both morphs and short-tongued bees (e.g.,Augochlorella spp.,Dialictus spp.) may be more common but as effective as pollinators as long-tongued bees (e.g.,Calliopsis andreniformis andHoplitis spp.). The conversion rate of flowers into capsules is only 13–17%. The spreading style in the short-styled morph is interpreted as an adaptation restricting insect-mediated, self-pollination but encouraging bee-stigma contact during nectar foraging.     

Pollen-expressed F-box gene family and mechanism of S-RNase-based gametophytic self-incompatibility (GSI) in Rosaceae

Many species of Rosaceae, Solanaceae, and Plantaginaceae exhibit S-RNase-based self-incompatibility (SI) in which pistil-part specificity is controlled by S locus-encoded ribonuclease (S-RNase). Although recent findings revealed that S locus-encoded F-box protein, SLF/SFB, determines pollen-part specificity, how these pistil- and pollen-part S locus products interact in vivo and elicit the SI reaction is largely unclear. Furthermore, genetic studies suggested that pollen S function can differ among species. In Solanaceae and the rosaceous subfamily Maloideae (e.g., apple and pear), the coexistence of two different pollen S alleles in a pollen breaks down SI of the pollen, a phenomenon known as competitive interaction. However, competitive interaction seems not to occur in the subfamily Prunoideae (e.g., cherry and almond) of Rosaceae. Furthermore, the effect of the deletion of pollen S seems to vary among taxa. This review focuses on the potential differences in pollen-part function between subfamilies of Rosaceae, Maloideae, and Prunoideae, and discusses implications for the mechanistic divergence of the S-RNase-based SI.     

A pre-European settlement pollen–climate calibration set for Minnesota, USA: developing tools for palaeoclimatic reconstructions

Aim The bias in modern North American pollen assemblages by landscape disturbance from Euro‐American settlement has long been overlooked in the construction of pollen–climate transfer functions. Our aim is to examine this problem and to develop an unbiased pre‐settlement pollen–climate transfer function, and to test its performance and inference power in comparison with commonly used techniques. Location Minnesota, USA, is of palaeoclimatic interest because within the state are located two continental‐scale ecotones, controlled by temperature and available moisture. Shifts of these ecotones can be tracked using palaeoecological techniques. Methods Using a data set of pre‐settlement pollen assemblages from 133 lakes, which were coupled to climate data from the earliest instrumental records (i.e. 1895–1924), a pre‐settlement pollen–climate data set was developed that lacked the influence of anthropogenic landscape disturbance. A corresponding modern pollen data set (from lake sediment core tops) and a modern climate (i.e. 1961–90) data set were also developed. The two pollen sets were compared to demonstrate the effects of landscape disturbance from human activities. Ordination (redundancy analysis with Monte Carlo permutation tests) and regression techniques (generalized linear modelling) were used to establish the relationships between the early instrumental climate variables and pre‐settlement pollen assemblages and individual taxa, respectively. Transfer functions for the most suitable climate variables (i.e. those forming a minimal set of non‐collinear climate variables that explained the greatest amount of pollen variance) were developed from the pre‐settlement data set using bootstrapping. Results Comparison of pre‐settlement pollen and modern pollen showed an over‐representation of Ambrosia, Chenopodiaceae and Poaceae, and an under‐representation of arboreal taxa (e.g. Pinus, Quercus, Ostrya) in the modern assemblages. Not surprisingly, ordination and regression techniques showed a strong relationship between the early instrumental climate variables and pre‐settlement pollen assemblages and taxa. Transfer functions were developed for May and February mean temperature and available moisture. Pre‐settlement transfer functions substantially improved the root mean squared error by 37–72% in comparison with modern transfer functions inferring pre‐settlement conditions, suggesting that the modern transfer functions have poorer predictive abilities. Main conclusions For climatic reconstructions, there can be a serious distortion of inferences based solely on modern pollen–climate data sets in regions where anthropogenic landscape disturbance has occurred. By using historical climate data, coupled with pre‐disturbance pollen assemblages, robust transfer functions for temperature and effective moisture were developed.     

Trends in pollen season characteristics of Alnus,Poaceae and Artemisia allergenic taxa in Bratislava,central Europe

Over the period 2002–2019, air temperature and precipitation significantly increased regionally for Bratislava, which could lead to phenological changes in some plant species. This study aimed to analyse the changes in the intensity, timing, and duration of pollen seasons of three allergological important plant taxa (Alnus, Poaceae, Artemisia) in the study area over 18 years. The pollen sampling was performed using a Hirst-type sampler. Mann–Kendall tau test was used to determine trends in pollen season characteristics, while Spearman’s correlation analysis was used to identify the relationships between the characteristics of pollen seasons and both air temperature and precipitation trends. The notable changes in the pollen-season-related features were observed for all analysed taxa. The Alnus pollen season now reaches the peak earlier and its intensity is rising in line with the summer-autumn temperature increasing trend, while unexpectedly intensity and duration of the Artemisia pollen season are declining in line with the increased precipitation and/or temperature trends. On the other hand, the intensity of the Poaceae pollen season is also declining, however, without statistically significant correlations with recorded increases in meteorological parameters considered. This phenomenon is probably related to both the reduction of the area of grasslands due to urbanization and the implementation of effective maintenance of urban green areas (e.g., timely mowing preventing the repeatedly flowering of grasses).

     

Development of a semi-automatic system for pollen recognition

A semi-automatic system for pollen recognitionis studied for the european project ASTHMA. The goal of such a system is to provideaccurate pollen concentration measurements. This information can be used as well by thepalynologists, the clinicians or a forecastsystem to predict pollen dispersion. At first,our emphasis has been put on Cupressaceae, Olea, Poaceae and Urticaceae pollen types. The system is composed of two modules: pollengrain extraction and pollen grain recognition. In the first module, the pollen grains areobserved in light microscopy and are extractedautomatically from a pollen slide coloured withfuchsin and digitized in 3D. In the secondmodule, the pollen grain is analyzed forrecognition. To accomplish the recognition, itis necessary to work on 3D images and to usedetailed palynological knowledge. Thisknowledge describes the pollen types accordingto their main visible characteristerics and tothose which are important for recognition. Somepollen structures are identified like the porewith annulus in Poaceae, the reticulum in Oleaand similar pollen types or the cytoplasm inCupressaceae. The preliminary results show therecognition of some pollen types, likeUrticaceae or Poaceae or some groups of pollentypes, like reticulate group.     

Pollen productivity estimates and relevant source area of pollen for selected plant taxa in a pasture woodland landscape of the Jura Mountains (Switzerland)

Relevant source area of pollen (RSAP) and pollen productivity for 11 key taxa characteristic of the pasture woodland landscape of the Jura Mountains, Switzerland, were estimated using pollen assemblages from moss polsters at 20 sites. To obtain robust pollen productivity estimates (PPEs), we used vegetation survey data at a fine spatial-resolution (1 × 1 m²) and randomized locations for sampling sites, techniques rarely used in palynology. Three Extended R value (ERV) submodels and three distance-weighting methods for plant abundance calculation were applied. Different combinations of the submodels and distance-weighting methods provide slightly different estimates of RSAP and PPEs. Although ERV submodel 1 using 1/d (d = distance in meters) best fits the dataset, PPE values for heavy pollen types (e.g. Abies) were sensitive to the method used for distance-weighting. Taxon-specific distance-weighting methods, such as Prentice’s model, emphasize the intertaxonomic differences in pollen dispersal and deposition, and are thus theoretically sound. For the dataset obtained in this project, Prentice’s model was more appropriate than other distance-weighting methods to estimate PPEs. Most of the taxa have PPEs equal to (Fagus, Plantago media and Potentilla-type), or higher (Abies, Picea, Rubiaceae and Trollius europaeus) than Poaceae (PPE = 1). Acer, Cyperaceae, and Plantago montana-type are low pollen producers. This set of PPEs will be useful for reconstructing heterogeneous, mountainous pasture woodland landscapes from fossil pollen records. The RSAP for moss polsters in this semi-open landscape region is ca. 300 m.     

Nectar and Pollen Sources for Honeybee （Apis cerana cerana Fabr.） in Qinglan Mangrove Area, Hainan Island, China

In the present study, nectar and pollen sources for honeybee （Apls cerana cerana Fabr.） were studied in Qlnglan mangrove area, Hainan Island, China, based on microscopic analysis of honey and pollen load （corblcular and gut contents） from honeybees collected In October and November 2004. Qualitative and quantitative melittopalynologlcal analysis of the natural honey sample showed that the honey is of unlfloral type with Mimosa pudlca L. （Mlmosaceae） as the predominant （89.14%） source of nectar and pollen for A. cerana cerana In October. Members of Araceae are an Important minor （3%-15%） pollen type, whereas those of Arecaceae are a minor （〈3%） pollen type. Pollen grains of Nypa fruticans Wurmb., Rhlzophora spp., Excoecarla agallocha L., Lumnitzera spp., Brugulera spp., Kandella candel Druce, and Ceriops tagal （Perr.） C. B. Rob. are among the notable mangrove texa growing In Qinglan mangrove area recorded as minor taxa In the honey. The absolute pollen count （I.e. the number of pollen grains/10 g honey sample） suggests that the honey belongs to Group V （〉1 000 000）. Pollen analysis from the corblcular and gut contents of A. cerana cerana revealed the highest representation （95.60%） of members of Sonneratia spp. （Sonneratlaceae）, followed by Bruguiera spp. （Rhizophoraceae）, Euphorblaceae, Poaceae, Fabaceae, Arecaceae, Araceae, Anacardlaceae, and Rublaceae. Of these plants, those belonging to Sonneratla plants are the most Important nectar and pollen sources for A. cerana cerana and are frequently foraged and pollinated by these bees in November.     

天门冬科黄精族细胞学研究进展

在全面收集和整理黄精族染色体数据的基础上,对国内外有关黄精族各类群间的染色体数目和倍性的变化规律进行了总结,并从染色体的多倍化和非整倍化与系统发育关系和地理分布方面探讨了黄精族内各属的起源和演化关系问题。黄精族包括黄精属、舞鹤草属、异黄精属和竹根七属,共约100余种,其中舞鹤草属(x=18)、异黄精属(x=16)和竹根七属(x=20)的染色体基数稳定,而黄精属染色体基数波动较大,主要为x=8~16,既有多倍化也有非整倍化现象。染色体数据表明黄精族4个属的染色体进化模式各不相同,揭示了黄精族内染色体从高基数向低基数演化的规律;各属内染色体的演化主要是体现在二倍体水平上的核型变异,多倍化在本族中不占主导地位;仅黄精属内伴有非常强烈的非整倍化现象;细胞学证据与分子系统发育的结果比较吻合,为黄精族内属间以及属下的系统发育与进化提供了重要的参考资料。     

Modern vegetation–pollen–climate relationships for the Pampa grasslands of Argentina

Aim To analyse the relationships between potential natural vegetation, pollen and climate in order to improve the interpretation of fossil pollen records and provide the background for future quantitative palaeoclimatic reconstructions. Location Pampa grasslands of Argentina, between 33–41° S and 56–67° W. Methods Modern pollen data were obtained from a pollen data base developed by the Grupo de Investigación de Paleoecología y Palinología, Universidad Nacional de Mar del Plata, Argentina (143 surface samples and 17 pollen types). Analysis of pollen and climate data involved multivariate statistics (cluster analysis and principal components analysis), scatter diagrams, Pearson’s correlation and isopoll mapping. Results Vegetation patterns at regional scales (grasslands and xerophytic woodlands) and local scales (edaphic communities) were identified by cluster analysis of pollen surface samples. The main climatic variables that appear to constrain the vegetation distribution and abundance of taxa are mean annual precipitation, annual effective precipitation and summer temperature. Individual pollen types such as Chenopodiaceae, Apiaceae, Cyperaceae, Prosopis, Schinus, Condalia microphylla and other xerophytic taxa are good indicators of moisture regime. Many pollen types are significantly correlated with summer temperature. The modern vegetation–pollen–climate relationships vary in a broadly predictable manner, supporting the contention that fossil pollen assemblages can be related to particular climatic characteristics. Main conclusions An expanded suite of modern analogues facilitated new insights into vegetation–pollen–climate relationships at the regional scale in Pampa grasslands. Relationships between individual pollen types and climate are appraised at a regional scale and new modern analogues are presented. The results provide the basis for improved vegetation and climate reconstruction from fossil records of the study area.     

石家庄市空气花粉散布规律及与气候因子的关系

石家庄市2007—2009连续两年空气花粉分析表明:受植物花期影响,春季以木本植物花粉为主,夏、秋季以草本植物花粉为主,不同类型花粉通量存在一定年际差异。松属、杨属、胡桃属等当地花粉含量占花粉组合的80.0%以上,桦木属、栎属、虎榛子属等区域花粉含量低于20.0%,显示空气花粉能较好地反映周围植被,但也受区域植被的影响。依据空气花粉通量变化规律,石家庄市主要空气花粉类型通量从高到低排在前5位的依次为:胡桃属、悬铃木属、蒿属、杨属、藜科,均为高致敏类型,花粉过敏症患者在其花期或通量较高时期应早作防范。空气花粉百分含量与气候因子之间的(CCA)分析结果显示,其主要受风速与水汽压影响;不同季节主要花粉类型通量与气候因子的相关分析表明:春季和秋季空气花粉通量主要受气温和水汽压的影响,夏季主要受相对湿度和水汽压的影响,冬季与气候因子相关较弱。     

Ultrastructure of pollen exine in centrospermous families

Transmission electron microscopy was utilized to examine pollen walls of selected taxa in theAizoaceae, Amaranthaceae, Basellaceae, Cactaceae, Chenopodiaceae, Didiereaceae, Halophytaceae, Nyctaginaceae, Phytolaccaceae, Portulacaceae, andCaryophyllaceae. This conspectus is an adjunct to scanning electron microscope observations of pollen surfaces and is directed towards elucidating the basic wall structure for these families. Although differences in internal morphology were observed at the inter- and intra-familial levels, they were interpreted as reflecting variations rather than major differences. The data indicate close morphological similarities of the first ten families enumerated above, i.e., those containing betalains. TheCaryophyllaceae, an anthocyanin family, indicated a slightly greater heterogeneity of pollen ultrastructure but not to the extent of disassociating it from the betalain families. In fact, this heterogeneity was rivaled by comparable heterogeneity among and within some of the betalain families. The conclusion is that all families have close pollen morphological relationships.Presented in the Symposium Evolution of Centrospermous Families, during the XIIth International Botanical Congress, Leningrad, July 8, 1975.