Can a stench be beautiful? – Osmophores in stem-succulent stapeliads (Apocynaceae-Asclepiadoideae-Ceropegieae-Stapeliinae)

Carrion flower stapeliads are examples of olfactory mimicry, forming sapromyiophilous flowers, which mimic food sources or oviposition sites to attract fly pollinators. The aim of this work was to investigate the ultrastructure of osmophores involved in the release of the carrion odor of Orbea variegata and Boucerosia indica flowers. In spite of their similar architecture (epidermal epithelium+subepidermal secretory layers), the osmophores of stapeliads feature some differences in morphology and ultrastructure. The epidermal epithelial cells of O. variegata and B. indica differ in shape, but both are extremely rich in endoplasmic reticulum and flocculent material in the vacuole. Unlike the Orbea, Boucerosia has starchless leucoplasts in the epidermal epithelium. Orbea features a cuticle with microchannels, while Boucerosia has a different mechanism for the pathway of scent substances to the cell exterior. They are released by rupturing of the outer layer of cuticle at the apex of the papillae. The epidermal cells of the adaxial corolla differ even between parts of the corolla, the corolla lobes and the annulus in the flower. This diversity may be connected with an odor gradient. The morphological and anatomical features of stapeliad (subtribe Stapeliinae) osmophores are generally similar to osmophores of members of subtribe Ceropegiinae (Ceropegia), thus, we suggest that this model of osmophores evolved before early diversification of Ceropegieae. The ultrastructural features of stapeliad osmophores are generally similar to those of Araceae, Orchidaceae and Passifloraceae.     

Breeding systems and pollination inVigna minima (Leguminosae,Papilionoideae)

Four types of floral breeding systems—(i) chasmogamy, (ii) aerial pseudocleistogamy, (iii) subterranean pseudocleistogamy and (iv) obligate subterranean true cleistogamy—are observed in the populations ofVigna minima inhabiting the Western Ghats (India). Five categories of phenotypes are recognized based on the number and kinds of floral breeding systems found in a given individual. The frequencies of different categories of phenotypes not only show intra- and interpopulation variation, but also fluctuate from generation to generation suggesting differences in the genetic structure of populations. This polymorphism in the breeding system of a single species is unique and may be adaptive. Obligate subterranean true cleistogamy and amphicarpy appear to be adaptations to jungle fires and soil erosion.—The flowers are of the flag-blossom type and insect visitors act as tripping agents. The tripping mechanism together with the polymorphic floral breeding system result in a balanced mixture of selfing and outcrossing. Such a recombination system may enhance the fitness ofV. minima which is essentially a colonizing species.     

Floral mimicry between Orchis israelitica Baumann and Dafni (Orchidaceae) and Bellevalia flexuosa Boiss. (Liliaceae)

Summary Orchis israelitica, which has no food reward, was found to share the pollinators of Bellevalia flexuosa: Eucera clypeata, Bombylius sp. and possibly also Anthophora sp. Since both species have a similar coloration pattern, flowering period and habitats — it is suggested that O. israelitica mimics the flowers of B. flexuosa as a deceit syndrome of pollination.Aspects of floral mimicry, with special attention to floral adaptations in the genus Orchis, are discussed.     

Pollination of the southwestern Opuntias

This paper presents an overview of pollination systems inOpuntia sens. lat. in the southwestern United States. The floral syndrome of large, colorful, bowl-shaped, diurnal flowers is present in all of the prickly-pear species and most of the cholla (Cylindropuntia) species in this area. Pollination by medium-sized and large bees is established for some of the species with this floral syndrome and is predicted for the others. The same floral syndrome is widespread inOpuntia in other geographical areas.—Deviations from this floral syndrome occur in certain species of southwestern chollas, one of which has nocturnal disc-shaped flowers, and in several tropical American species groups or segregate genera with red hummingbird flowers. But such cases are relatively infrequent. Divergence between species with respect to floral syndrome and pollination system is not a common feature in the evolutionary pattern ofOpuntia. Pollination of North American Cacti, IV.—Previons parts of this series:Grant & Grant 1979a,Grant & al. 1979,Grant & Grant 1979b.     

Systématique des Saccharomyces: Osidases et besoins vitaminiques

A study of the genus Saccharomyces by new biocharacters demonstrates indirectly the genotype of each species; intracellular osidases (lactose — maltose — cellobiase — melibiase — invertase — trehalase) and vitamine requirements (biotin — folic acid — inositol — niacine — pantothénate —para-aminobenzoïc acid — pyridoxine — thiamine) reveal some phylogenetic links between the species. It appears that Van der Walt's group I is very homogeneous and must be restricted to only 7 species. The Torulospora group seems very similar to the genus Debaryomyces when vitamine needs and osidases are considered; the relations between the 2 groups are discussed. When other biocharacters are studied (nitrite reductase-immunological properties, etc. ...) the value in the GC content (4–5% lower in Debaryomyces) will be established.These results confirm that intracellular osidases and vitamine needs are very valuable tools for systematic criteria.

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Collaboration technique: Mme Billon-Grand.     

Evolution and diversity of floral scent chemistry in the euglossine bee-pollinated orchid genus Gongora

•Background and Aims Animal-pollinated angiosperms have evolved a variety of signalling mechanisms to attract pollinators. Floral scent is a key component of pollinator attraction, and its chemistry modulates both pollinator behaviour and the formation of plant–pollinator networks. The neotropical orchid genus Gongora exhibits specialized pollinator associations with male orchid bees (Euglossini). Male bees visit orchid flowers to collect volatile chemical compounds that they store in hind-leg pouches to use subsequently during courtship display. Hence, Gongora floral scent compounds simultaneously serve as signalling molecules and pollinator rewards. Furthermore, because floral scent acts as the predominant reproductive isolating barrier among lineages, it has been hypothesized that chemical traits are highly species specific. A comparative analysis of intra- and inter-specific variation of floral scent chemistry was conducted to investigate the evolutionary patterns across the genus.•Methods Gas chromatography–mass spectrometry (GC-MS) was used to analyse the floral scent of 78 individuals belonging to 28 different species of Gongora from two of the three major lineages sampled across the neotropical region. Multidimensional scaling and indicator value analyses were implemented to investigate the patterns of chemical diversity within and among taxonomic groups at various geographic scales. Additionally, pollinator observations were conducted on a sympatric community of Gongora orchids exhibiting distinct floral scent phenotypes.•Key Results A total of 83 floral volatiles, mainly terpenes and aromatic compounds, were detected. Many of the identified compounds are common across diverse angiosperm families (e.g. cineole, eugenol, β-ocimene, β-pinene and terpinen-4-ol), while others are relatively rare outside euglossine bee-pollinated orchid lineages. Additionally, 29 volatiles were identified that are known to attract and elicit collection behaviour in male bees. Floral scent traits were less variable within species than between species, and the analysis revealed exceptional levels of cryptic diversity. Gongora species were divided into 15 fragrance groups based on shared compounds. Fragrance groups indicate that floral scent variation is not predicted by taxonomic rank or biogeographic region.•Conclusions Gongora orchids emit a diverse array of scent molecules that are largely species specific, and closely related taxa exhibit qualitatively and quantitatively divergent chemical profiles. It is shown that within a community, Gongora scent chemotypes are correlated with near non-overlapping bee pollinator assemblies. The results lend support to the hypothesis that floral scent traits regulate the architecture of bee pollinator associations. Thus, Gongora provides unique opportunities to examine the interplay between floral traits and pollinator specialization in plant–pollinator mutualisms.     

Floral scent and intrafloral scent differentiation inMoneses andPyrola (Pyrolaceae)

Floral scent was collected by headspace methods from intact flowers, petals, and stamens of four species ofPyrolaceae. The scent samples were analyzed by coupled gas chromatography-mass spectrometry (GC-MS). The floral scent inPyrola spp. is differentiated into a characteristic petal scent—phenyl propanoids and a characteristic stamen scent—methoxy benzenes. InMoneses the scent is characterized by isoprenoids and benzenoids, with a larger proportion of benzenoids in the stamens compared to the petals. Specific anther scents may promote foraging efficiency in buzz-pollinated species and enhance flower fidelity. Variation in floral scent composition is consistent with the taxonomic relationships among the genera and species examined.     

Ultrahistochemische Untersuchungen an der Glykokalyx von Lymphozyten aus dem Ductus thoracicus der Ratte

Zusammenfassung Die Lymphozyten des Ductus thoracicus sind mit einer ca. 120 nm dicken extrazellulären Sialoglykoproteinschicht umgeben, die nicht bei allen Zellen gleich gut ausgebildet ist. Mit Hilfe ihrer Thoriumbindungskapazität lassen sich zwei Zellgruppen voneinander unterscheiden. Die erste Gruppe — 90–92 % — bindet sehr viel Thoriummizellen an ihrer Oberfläche, während eine geringe Anzahl von Zellen — 6–8 % — nur wenig kolloidales Thorium bindet. Mögliche Zusammenhänge zwischen der Glykokalyx, der Aufgabe, der Herkunft und der Lebensdauer der Lymphozyten werden diskutiert.

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Ultrahistochemical studies on the glycocalyx of the thoracic duct lymphocytes

Summary The thoracic duct lymphocytes are coated by an extracellular sialoglycoprotein which is not equally well developed in all of the cells. Using the capacity of the lymphocytes of binding thorotrast particles to their surface one can separate two cell populations. One group — representing about 90–92 % — is characterized by binding a considerable amount of thorotrast, while a smaller group — ca. 6–8 % — binds only few thorium particles. The possible connection between the glycocalyx, the function, the origin and the life span of the lymphocytes is discussed.

     

Carotenoids in floral parts of a narcissus, a daffodil and a tulip

1. The qualitative and quantitative distribution of carotenoids of the floral parts of three monocotyledons, the narcissus Scarlet Elegance, the daffodil King Alfred and the tulip Golden Harvest, were studied. β-Carotene, lutein or epoxy-β-carotenes were usually the main pigments, depending on the floral part and on the flower. When β-carotene was the major pigment there were only small amounts of, or sometimes no, epoxycarotenes. 2. Anthers, stigmas and styles of the three flowers did not possess any specific carotenoids but in some cases contained appreciable amounts of epoxycarotenoids. The possibility that these take part in reproduction is discussed. 3. The generalization that yellow flowers contained large amounts of xanthophylls and only traces of carotenes, whereas deep-orange flowers seemed to be characterized by the presence of large amounts of one carotene, was not always the correct one. It is suggested that the floral parts are yellow or orange depending on what carotenoids are present, which is the major one and the amount of total carotenoids, and also on the presence of other non-carotenoid pigments. 4. Two new probable isomers of 5,6:5′,6′-diepoxy-β-carotene were isolated and found together in various floral parts of the tulip Golden Harvest.     

Multimodal Floral Signals and Moth Foraging Decisions

Background

Combinations of floral traits – which operate as attractive signals to pollinators – act on multiple sensory modalities. For Manduca sexta hawkmoths, how learning modifies foraging decisions in response to those traits remains untested, and the contribution of visual and olfactory floral displays on behavior remains unclear.

Methodology/Principal Findings

Using M. sexta and the floral traits of two important nectar resources in southwestern USA, Datura wrightii and Agave palmeri, we examined the relative importance of olfactory and visual signals. Natural visual and olfactory cues from D. wrightii and A. palmeri flowers permits testing the cues at their native intensities and composition – a contrast to many studies that have used artificial stimuli (essential oils, single odorants) that are less ecologically relevant. Results from a series of two-choice assays where the olfactory and visual floral displays were manipulated showed that naïve hawkmoths preferred flowers displaying both olfactory and visual cues. Furthermore, experiments using A. palmeri flowers – a species that is not very attractive to hawkmoths – showed that the visual and olfactory displays did not have synergistic effects. The combination of olfactory and visual display of D. wrightii, however – a flower that is highly attractive to naïve hawkmoths – did influence the time moths spent feeding from the flowers. The importance of the olfactory and visual signals were further demonstrated in learning experiments in which experienced moths, when exposed to uncoupled floral displays, ultimately chose flowers based on the previously experienced olfactory, and not visual, signals. These moths, however, had significantly longer decision times than moths exposed to coupled floral displays.

Conclusions/Significance

These results highlight the importance of specific sensory modalities for foraging hawkmoths while also suggesting that they learn the floral displays as combinatorial signals and use the integrated floral traits from their memory traces to mediate future foraging decisions.     

Ecological science and the management of protected areas

This paper aims to survey a few among many ecological principles that are particularly relevant to the management of protected areas. Various aspects of the relation between area of protected habitat and numbers of constituent species preserved are discussed, with emphasis of edge effects and other factors. Particular attention is given to those species which persist via local extinctions and recolonizations within a shifting mosaic of patches, and to the counter-intuitive things that can happen to such species or communities when a fraction of the patches is destroyed. The paper concludes with comments about making choices as to which areas to preserve — the calculus of biodiversity — and about more general social and economic considerations.     

Localization and characteristics of parasympathetic preganglionic neurons in the sacral spinal cord

Antidromic responses of parasympathetic preganglionic neurons (PPN) in the sacral spinal cord evoked by stimulation of the pelvic nerve were studied in acute experiments on anaesthetized and immobilized cats by means of extracellular recording technique. The conduction velocities for preganglionic axons were calculated from the latency of these responses. It was shown that the upper limits of the conduction velocities for sacral parasympathetic axons extended the range (limit 12–15 m/sec) previously described: The velocities varied from 0.9 to 30.5 (mean 11.3±0.47) m/sec. According to the axonal conduction velocities the PPN were divided into four groups: the first group with conduction velocities from 0.9 to 3.0 m/sec; the second — 4.0–12; the third — 13–21; and the fourth group — 21–30 msec. PPN of the second group quantitatively prevailed — 57.6%, those of the third group represented 29.9%, and those of the first and fourth groups 6.8 and 6.2% of the total amount of PPN, respectively. Relative topic specialization of the second and third PPN groups was revealed. The density of PPN distribution in the intermediolateral region was higher in the second group than in the third one, while in ventral parts of the ventral horn concentration of the third PPN group was higher than that of other groups. The functional significance of PPN from the third group with fast-conducting axons (the conduction velocities correspond to those of group B fibers) is discussed.Translated from Neirofiziologiya, Vol. 25, No. 1, pp. 39–45, January–February, 1993.     

The evolution of signal–reward correlations in bee- and hummingbird-pollinated species of Salvia

Within-individual variation in floral advertising and reward traits is a feature experienced by pollinators that visit different flowers of the same plant. Pollinators can use advertising traits to gather information about the quality and amount of rewards, leading to the evolution of signal–reward correlations. As long as plants differ in the reliability of their signals and pollinators base their foraging decisions on this information, natural selection should act on within-individual correlations between signals and rewards. Because birds and bees differ in their cognitive capabilities, and use different floral traits as signals, we tested the occurrence of adaptive divergence of the within-individual signal–reward correlations among Salvia species that are pollinated either by bees or by hummingbirds. They are expected to use different floral advertising traits: frontal traits in the case of bees and side traits in the case of hummingbirds. We confirmed this expectation as bee- and hummingbird-pollinated species differed in which specific traits are predominantly associated with nectar reward at the within-individual level. Our findings highlight the adaptive value of within-individual variation and covariation patterns, commonly disregarded as ‘environmental noise’, and are consistent with the hypothesis that pollinator-mediated selection affects the correlation pattern among floral traits.     

Hume and the argument for biological design

There seems to be a widespread conviction — evidenced, for example, in the work of Mackie, Dawkins and Sober — that it is Darwinian rather than Humean considerations which deal the fatal logical blow to arguments for intelligent design. I argue that this conviction cannot be well-founded. If there are current logically decisive objections to design arguments, they must be Humean — for Darwinian considerations count not at all against design arguments based upon apparent cosmological fine-tuning. I argue, further, that there are good Humean reasons for atheists and agnostics to resist the suggestion that apparent design — apparent biological design and/or apparent cosmological fine-tuning — establishes (or even strongly supports) the hypothesis of intelligent design.     

The chemical nature of fetid floral odours in stapeliads (Apocynaceae-Asclepiadoideae-Ceropegieae)

By emitting strong fetid scents, sapromyiophilous flowers mimic brood and food sites of flies to attract them as pollinators. To date, intensive comparative scent analyses have been restricted to sapromyiophilous Araceae. Here, we analysed flower volatiles of fetid stapeliads to improve our understanding of the floral biology of fly pollinated species, and to learn whether mimicry types comparable to those found in Araceae exist. Floral volatiles of 15 species out of 11 genera within the Asclepiadoideae-Ceropegieae-Stapeliinae were collected via headspace adsorption and thermal desorption and analysed by gas chromatography-mass spectometry (GC-MS). Data were analysed using CNESS-NMDS statistics. Sapromyiophilous stapeliads are highly diverse in their scent composition, in which sulphur compounds, benzenoids, fatty acid derivatives or nitrogen-containing compounds dominate. Four groups are evident: species with high p-cresol content but low amounts of polysulphides (herbivore faeces mimicry); species with mainly polysulphides and low amounts of p-cresol (carnivore/omnivore faeces or carcass mimicry); species with high amounts of heptanal and octanal (carnivore/omnivore faeces or carcass mimicry); and species with hexanoic acid (urine mimicry). Considering the findings in the unrelated Araceae, our results support the universality of different mimicry types that are obviously subsumed under the sapromyiophilous syndrome.     

Fine structure of the giant aflagellate spermatozoon in pseudostomum quadrioculatum (leuckart) (platyhelminthes,prolecithophora)

The giant aflagellate spermatozoa of P. quadrioculatum are composed of two different parts: a thicker head piece and a more slender tail piece. In the head there exist a large elongated nucleus and an elongated mitochondrial derivative situated in a groove-like cavity of the nucleus. In mature spermatozoa the nuclear material is arranged in many small membrane bounded areas. Both structures, nucleus and mitochondrial derivative, are spirally coiled. The outer part of the membrane in the mitochondrial derivative forms many loop-like foldings. Both organelles continue to the tail in form of two small, helically coiled ribbons; the nucleus is anchored within the mitochondrial derivative by an electron-opaque process. A sheath of spirally-orientated cortical microtubules starting from the tip of the head runs to the tip of the tail under the cell membrane. In addition, a second sheath of tubules occurs in the tail region, these tubules also run parallel to each other, but in the opposite direction to the microtubules of the outer sheath.The possible relations between the structures observed and the motility of the spermatozoa are discussed; in addition, some phylogenetic comments are attempted.Abbreviations c — cerebrum - com — cortical microtubules - cop — copulatory organ - fm — foldings of the mitochondrial membrane - l — lattice - mid — mitochondrial derivative - mt — microtubules - n — nucleus - ne — nuclear envelope - ph — pharynx - pn — protonephidium - rp — ribbon-like nuclear process - te — testis - tt — testis - tt — tip of the tail - vi — vitellarium - vs — vesicula seminalis     

Postconflict Behavior Among Male Japanese Macaques

Reconciliation was first described more than 20 years ago. Since then, it has been observed in many mammals (mainly primates) but data on postconflict behavior among males are still scarce because they usually aggressively compete for mating partners, rarely maintain amicable relationships with one another. Accordingly, reconciliation is expected to occur at low rates. Although this is true for Japanese macaque males, the subspecies on Yakushima Island (Macaca fuscata yakui) seems to represent an exception as grooming among males occurs often. We analyzed postconflict behavior among them and discuss the possible factors that may favor the occurrence of grooming and reconciliation. Selective attraction between former opponents—reconciliation—occurred soon after conflicts. Consolation—affiliative interactions between a focal animal and group members other than the former opponents occurring earlier in PCs than in MCs—was absent among males. Conciliatory tendency is higher for Yakushima macaque males (0.31) versus that in studies on the other subspecies Macaca fuscata. We discuss differences in the behavioral ecology of the 2 subspecies, the ecological and social factors that may favor the occurrence of reconciliation, and the possible benefits that males gain from grooming exchange and reconciliation.     

Establishment of Plantago lanceolata L. and Plantago major L. among grass

Summary Establishment of Plantago lanceolata and P. major ssp major among grass was studied in a field experiment in which survival and selection on date of seedling emergence and plant size was investigated in relation to the vegetation structure. P. major — in contrast to P. lanceolata — was not able to establish itself in grass because of its lower competitive ability caused by later germination, smaller seedling size, and shorter leaves. In both species there was selection for early germination. For P. lanceolata a significant correlation was found between the strength of selection and the light climate, determined by the structure of the grass sward. Plants that germinated early were at an advantage because they were larger, especially the leaves, when compared with plants that germinated late. It seems likely that selection was mainly by competition for light. Contrary to expectation P. major-seedlings had a higher shade tolerance than those of P. lanceolata. The performance of both species is discussed in relation to their different life strategies.Grassland species research group publication no 142     

Vergleichende Braunwasser-Teichstudien im niederösterreichischen Waldviertel

Summary Three groups of fishponds with brown water were studied during 1967–1970: A — fishponds in natural state on crystalline rocks, B — medium managedfishponds on tertiary formations, C — extensively managed peat-bog-like ponds on Cordioritgneis. The first group consists of extremely poor oligomineral ponds, pH never reaching 7, with an average transparency of 1 m, with maximum alkalinity 0,16 mval/l and with the cladoceran Holopedium gibberum in the plankton. The second group is treated with line and fertilizers, so that pH oscillates near 7, alkalinity between 0,4–1,44 mval/l and feeble water blooms occur in October and November, consisting of Aphanizomenon flos-aquae, Anabaena scheremetievi and Chrysopyxis paludosa. The third group comprises highly brownish colored pond with an average transparency of 69 cm. Many interesting algae were reported from these ponds, among them some new for science. Lists of phytoplankton and zooplankton show great numbers of species. Diatoms are characteristic for the first group, Chlamydomonas species for the second one. The rotifer Trichotria truncata is considered a glacial relict. Many of the Diatoms and Chrysophyceans prefer low light intensity and are thus able to live in the brown-water ponds, where the light is absorbed within a few meters.