Interactive 3D anatomy and affinities of the Hyalogyrinidae,basal Heterobranchia (Gastropoda) with a rhipidoglossate radula

Whereas Hyalogyrina Marshall, 1988 was originally considered a skeneid vetigastropod, the family Hyalogyrinidae Warén & Bouchet, 1993 has later been classified as basal Heterobranchia despite their rhipidoglossate radula. In order to evaluate this placement and to shed more light on the origin of all higher Gastropoda, we investigated five representatives of all three nominal hyalogyrinid genera by means of semithin serial sectioning and computer-aided 3D reconstruction of the respective anatomy, which we present in an interactive way. In general the morphological features (shell, external morphology, anatomy) fully confirm the placement of Hyalogyrinidae in the Heterobranchia, but in particular the conditions of the genital system vary substantially within the family. The ectobranch gill of Hyalogyrinidae is shared with Valvatidae, Cornirostridae, and Xylodisculidae; consequently all these families are united in Ectobranchia Fischer, 1884. The rhipidoglossate hyalogyrinid radula suggests independent acquisition of taenioglossate radulae in the Caenogastropoda and other Ectobranchia. Therefore, the origin of the Heterobranchia—and thus of all higher gastropods—looks to have taken place already on the rhipidoglossate, i.e. the ‘archaeogastropod’, level of evolution. Ectobranchia are considered the first extant offshoot of the Heterobranchia; implications for the stem species of the latter are outlined.     

Effect of in vivo administered plant growth hormones on the development of amylase and protease during germination of indian bean (Dolichos lablab L. var. lignosus) seeds

The plant growth hormones — BA, GA₃ or IAA (alone or in combination) in single dose were injected into the centre of intact imbibed seed, germinated in the presence of water and monitored for root length, shoot length, and activities of α-amylase and proteases during a 10-day germination period of Indian bean seeds. A significant increase was noticed in the root length and shoot length compared to the respective controls. Injection of BA, GA₃ or IAA alone resulted in a significant increase in the activity of α-amylase. The increase in the activities of proteases (acidic, neutral and alkaline) was not affected with either BA or GA₃ during the early stage of germination, but the fall in their activities in the later stages of germination was suppressed. However, in vivo administration of IAA alone or in combination with BA or GA₃ resulted in faster and higher development of α-amylase and protease(s) activities. These results indicated that more than one hormone is necessary for inducing the development of α-amylase and proteases at early stages, and also responsible for maintaining the higher activities in the later stages of germination.     

Germination and development of Mimosa pilulifera in petroleum-contaminated soil and bioremediated soil

In 2000 there was an oil spill at the Getúlio Vargas Refinery (REPAR/PETROBRÁS) in Paraná, Brazil. Nearly five years after contamination and the use of bioremediation, a study was carried out to identify the effects of the contaminated soil and the bioremediated soil on the germination and initial growth of Mimosa pilulifera seedlings. The experiment consisted of three treatments: petroleum-contaminated soil, bioremediated soil and uncontaminated soil, with five repetitions each. The following measurements were taken after 30, 60 and 90 days of planting: the percentage of germination, biomass and leaf area of the eophylls, biomass and length of the shoot and the roots in addition to the shoot/root ratio. The percentage of germination and the root biomass were not affected by the contaminated soil or by the bioremediated soil. On both the contaminated soil and the bioremediated soil biomass and leaf area of the eophyll were reduced. Plant length and shoot biomass were lower in the contaminated soil. Furthermore, the effect of the contaminated soil and the bioremediated soil was greater in the shoot than in the root system, since the bioremediation reduced the toxicity of the petroleum-contaminated soil.     

Developmental Morphology of the Flower in Narcissus

The inferior ovary of Narcissus has been shown to be appendicularin origin from studies of both its vascular anatomy and ontogeny.The corona which arises above the insertion of the stamens afterthe completion of the other floral members is considered tobe formed by the fusion of ligular outgrowths of the perianthsto form a cup and having its vascular bundles in reverse orientationto those in the perianth. In both Narcissus tazetta and N pseudonarcissusthe style is hollow throughout and there are 2–6 layersof transmitting tissue in the stigma and one layer in the style.Correlation between the ovary type and the fruit type was discussed.     

Divergence in germination traits among arctic and alpine populations of <Emphasis Type="Italic">Koenigia islandica</Emphasis>: light requirements

Light is known to regulate conservative germination strategies and the formation of seed banks. Although these strategies are crucial to survival in tundra environments—especially for annuals—light requirements for germination in arctic–alpine species are seldom investigated. Furthermore, environmental differences between arctic and alpine regions are expected to lead to evolutionary divergence among conspecific populations in seed germination strategies. In this study, we report important differences in germination light requirements among six arctic and alpine populations of the annual Koenigia islandica. Light had little effect on germination of the seeds from Iqaluit (Nunavut, Canada), Yukon (Canada), and Jasper (Alberta, Canada), whereas the seeds from the most severe climates, Svalbard (Norway) and Colorado (USA), had strong light requirements. Stratification of the seeds had little influence on their germination light requirements, with the exception of the population from Dovre (Norway), in which it induced a strong light requirement. Possible adaptive explanations and some implications of these observed germination patterns are discussed.     

High apex predator biomass on remote Pacific islands

On coral reefs in Palmyra—a central Pacific atoll with limited fishing pressure—total fish biomass was 428 and 299% greater than on reefs in nearby Christmas and Fanning Islands. Large apex predators, groupers, sharks, snappers, and jacks larger than 50 cm in length, accounted for 56% of total fish biomass in Palmyra on average, but only 7 and 3% on Christmas and Fanning. These biomass proportions are remarkably similar to those previously reported for the remote and uninhabited Northwest Hawaiian Islands (NWHI) and densely populated Main Hawaiian Islands (MHI), although Palmyra’s reefs are dominated in biomass by sharks (44% of the total), whereas the NWHI by jacks (39%). Herbivorous fish biomass was also greater on Palmyra than on Christmas and Fanning (343 and 207%, respectively). These results and previous findings indicate that remote, uninhabited islands support high levels of consumers, and highlight the importance of healthy coral reef ecosystems as reference points for assessment of human impacts and establishment of restoration goals.     

A latex lectin from <Emphasis Type="Italic">Euphorbia trigona</Emphasis> is a potent inhibitor of fungal growth

In this study we identified and characterized a major latex lectin — designated as EtLLH — with antimicrobial activity from the succulent African milk tree Euphorbia trigona. The lectin is highly concentrated in the latex of E. trigona and appears to be composed of at least two subunits with a molecular mass of 32 kDa. EtLLH shares significant similarities to known plant lectins — ricin from Ricinus communis and agglutinin from Viscum album coloratum — which specifically bind D-galactose and N-acetyl-D-glucosamine, the major building blocks of many fungal cell walls. Antimicrobial activity assays revealed an impact of EtLLH on three phytopathogenic filamentous ascomycetes. The germination of the conidiospores and the hyphal growth of Aspergillus niger and Fusarium graminearum were severely inhibited by EtLLH already at concentrations below 0.1 mg cm⁻³, while the effect on germination of the melanized conidiospores of Botrytis cinerea was less significant.     

Effects of Light,Temperature, and Water Depth on Growth of a Rare Aquatic Plant, <Emphasis Type="Italic">Ranunculus kadzusensis</Emphasis>

Ranunculus kadzusensis is an endangered aquatic plant species that commonly reproduces in the rice paddies of Korea and Japan during winter and early spring. Here, we investigated the effects of main aquatic environmental factors—light, temperature, and water depth—on its growth, with the goal of seeking information that will contribute to its in situ conservation. As the amount of shading increased, biomass, maximum shoot length, number of branches, flowers, and fruits, main stem diameter, and maximum leaf length decreased. Although seed germination occurred under a 12-h photoperiod and at either 30/20°C (day/night) or 20/15°C, most plants died at the higher temperature. Survival was 0% for surface-grown plant sets when tested in a wintertime pond experiment. The rate of maximum shoot extension was greatest for plants grown at depths of 50 and 100 cm versus those at 20 cm. Thus, we demonstrated that R. kadzusensis is intolerant of high temperatures and shade, which may explain why its growth is limited to paddies with no shading and where temperatures are low early in the year, before rice cultivation begins.     

Carboxypeptidases of germinating triticale grains

Presence of five carboxypeptidases was found in endosperm of germinating triticale grains, while two of them in scutellum. Changes of their activities during four days of germination suggest that carboxypeptidase II plays an important role at initial stage of germination, while carboxypeptidases I and III - at subsequent stages of the process. High activity of carboxypeptidase II both in scutellum and endosperm of dry grains accompanied by its decrease during germination, and on the other hand, the appearance of carboxypeptidases I and III activities at the 2^nd and 3^rd day of the process seems to confirm such functions of these enzymes. Experiments with GA₃ indicated that carboxypeptidase I was synthesized in scutellum, and carboxypeptidase III — in aleurone layer. Carboxypeptidases I and II cleave N-CBZ-Phe-Ala, and carboxypeptidase III — N-CBZ-Ala-Met and N-CBZ-Ala-Phe as substrates with the highest rate.     

A novel dual-phase culture medium promotes germination and seedling establishment from immature embryos in South African <Emphasis Type="Italic">Disa</Emphasis> (Orchidaceae) species

In vitro germination as a conservation aid demands propagation systems that yield increasingly larger numbers of plants as rapidly as possible. However, summer-rainfall Disa species are germinated infrequently under asymbiotic conditions. Attempts to bypass impermeable testae in these species resulted in the formulation of a dual-phase protocol—with the specific aim of increasing water availability to the embryo. Dual-phase cultures were initiated using seed from green capsules and comprised a solid, charcoal-rich medium overlaid with a reduced strength, liquid medium fraction of the same type. The former served to negate the influence of leached phenols and allowed protocorms to establish polarity, whilst the latter increased water availability. The dual-phase protocol germinated nine Disa species (including D. cooperi, D. nervosa, D. pulchra and D. woodi); representing five first time reports (D. brevicornis, D. crassicornis, D. patula, D. stachyoides and D. versicolor). Furthermore, germination was comparatively rapid and percentages for most species approached their estimated germination potential (∼viability). Congruency here suggests that dual-phase conditions are amenable to germinating a number of seeds that reflects the maximum number of viable embryos—critical for conservation efforts.     

The seminal root primordia in barley and the participation of their non-meristematic cells in root construction

In addition to the primary seminal primordium, the so-called secondary seminal root primordia are also initiated in a barley embryo. The primary root primordium is developmentally most advanced. It is formed by root meristem covered with the root cap, and by a histologically determined region with completed cell division. On germination, the restoration of growth processes begins in this non-meristematic region of root primordium by cell elongation, with the exception of the zone adjacent to the scutellar node, the cells of which do not elongate but continue differentiating. In the root primordia initiated later, the zone with completed cell division is relatively shorter, in the youngest primordia the non-meristematic cells may be lacking. The root meristem is reactivated after the primary root primordium has broken through the sheath-like coleorrhiza and emerges from the caryopsis as the primary root. The character of root meristem indicates a reduced water content at the embryonic development of root primordium. With progressing growth the root apex becomes thinner, the meristematic region becomes longer, and the differences in the extent of cell division between individual cell types increase. — The primary root base is formed of cells pre-existing in the seminal root primordium. Upon desiccation of caryopsis in maturation, and subsequent quiescent period, their development was temporarily broken, proceeding with the onset of germination. The length of this postembryonically non-dividing basal zone is different in individual cell types. The column of central metaxylem characteristic of the smallest number of cell cycles, has, under the given conditions, a mean length of about 22 mm, whereas the pericycle, as the tissue with most prolonged cell division, has a mean length of about 6 mm. In the seminal root primordia initiated later the non-dividing areas are relatively shorter. The basal region of seminal roots thus differs in its ontogenesis from the increase which is formed “de novo” by the action of root meristem upon seed germination.     

Salt tolerance of barley (Hordeum vulgare L.) cultivars at the germination stage: Analysis of the response functions

Two models, initially proposed by Van Genuchten (1983) for evaluating salinity-yield response curves at the adult stage, were applied to study the salinity response of 24 barley cultivars at the germination stage. According to the calculated salinity threshold, EC_t (the solution electrical conductivity, EC, at which germination starts to decrease), and EC₅₀ (the solution EC at which germination is reduced by 50%) parameters, both models give similar results, although model 2, a sigmoid-form curve, fits the observed data slightly better than model 1, a piecewise response function. Also, the results suggest that, for model 1, EC_t seems to be the most reliable parameter for screening barley germplasm because it clearly discriminates the relative salt-tolerance of the studied cultivars and, furthermore, it basically determines their salinity response for the 100 to 50% germination interval. On the other hand, the model 1 s parameter — percent germination decrease per unit salinity increase bove EC_t—is less relevant because of its smaller variation interval and lack of correlation with EC₅₀, indicating that the salinity response of the studied cultivars for the 50% germination value is independent of this parameter.     

Avian gut-passage effects on seed germination of shrubland species in Mediterranean central Chile

Effects of avian gut-passage on seed germination are important to assess the effectiveness of frugivores in woodland regeneration, particularly in biodiversity hotspots that have a high incidence of avian frugivory. We examined the effect of avian gut-passage on seed germination in contrast to seeds that remain uneaten in five shrub species in Mediterranean central Chile and sought to determine the physiological mechanism(s) by which seed germinability is modified. Germination assays were conducted in a glasshouse for five common shrub species of the sub-Andean matorral: Azara dentata (Flacourtiaceae), Schinus polygamus and Schinus molle (Anacardiaceae), Cestrum parqui (Solanaceae), and Maytenus boaria (Celastraceae). We estimated germinability (final percent germination), dormancy length (time from sowing to first germination), mean length of dormancy of all germinated seeds, and contrasted germination rates of defecated versus manually extracted and pulp-enclosed seeds. Avian gut-passage increased seed germinability in four of the five shrub species studied—primarily through deinhibition via pulp removal. Minimum dormancy length was not modified by avian gut-passage for A. dentata, but was significantly shorter for S. molle and C. parqui. Mean dormancy length was significantly shorter in gut-passed seeds of A. dentata, S. molle and M. boaria. Avian gut-passage greatly enhanced the seed germination rates of three species, A. dentata, S. molle and C. parqui. We conclude that the positive effects of birds on seed germination facilitate the regeneration of sub-Andean shrublands, and that bird declines due to landscape change may impair recovery rates of successional or restored areas due to dispersal limitation.     

Question 3: The Problem of Macromolecular Sequences: The Forgotten Stumbling Block

The Author agrees in principle with the question/statement, but states also that an important qualification is needed within this question. In fact, it is not possible by the bottom up approach to find the conditions for the synthesis of our actual proteins—lysozyme, chymotrypsin or the like—however it is possible to show experimentally that co-oligopeptides chains of that length can be produced by prebiotic reactions. Considering such a synthesis, it is important to recall that proteins—and nucleic acids—are not simply polymers, but are co-polymers, and the kinetics and thermodynamics attending the synthesis of copolymers poses stringent constraints for the biogenesis and growth of specific sequences. Such constraints are examined and discussed. Presented at: International School of Complexity–4th Course: Basic Questions on the Origins of Life; “Ettore Majorana” Foundation and Centre for Scientific Culture, Erice, Italy, 1–6 October 2006.     

Genetic variation for in vitro sesame pollen germination and tube growth

  In vitro pollen germination and tube length studies are valuable in elucidating mechanisms (germination capacity and rate, tube growth rate) possibly associated with genetic differences in male transmission. On each of two collection dates, the percentage germination and tube length of the binucleate pollen grains from five diverse sesame (Sesamum indicum L.) genotypes were determined at eight times (30, 60, 90, 120, 150, 180, 240, 300 min) after inoculation on a semisolid medium containing 10% (100 g l^-1) sucrose (C₁₂H₂₂O₁₁), 0.4% (4 g l^-1) purified agar (Fisher Lot 914409), 0.1% (1 g l^-1) calcium nitrate [Ca(NO₃)₂ ⋅ 4H₂O] and 0.01% (100 mg l^-1) boric acid (H₃BO₃). Before heating, the pH of the medium was adjusted to 7.0 with a 0.1 N potassium hydroxide (KOH) solution. Over the five genotypes, 5% germination was found 30 min after inoculation and a maximum of 37% germination 120 min after inoculation with no significant changes thereafter. As indicated by the highly significant genotype×time after inoculation interaction, the genotypes differed in the time at which germination was initiated and maximum germination attained. Over all five genotypes, the tube length was 91 μm 30 min after inoculation, reaching a maximum of 1000 μm 300 min after inoculation. As shown by the highly significant genotype×time after inoculation interaction, the genotypes differed in the time at which tube length was observed and the maximum tube length was attained. Little or no relationship between percent germination and tube length was observed among the genotypes. For both percent germination and tube length, the statistical significance of collection date and its interactions with genotype and time after inoculation indicated that environment in the form of collection date was also an influencing factor. These results indicated that genetic differences among genotypes were present for in vitro germination capacity, germination rate and tube growth rate and that these factors singly or in combination could alter male transmission of genetic elements. Received: 5 February 1997 / Accepted: 23 June 1997     

First Finding of Ornithodiplostomum scardinii (Schulman, 1952) Sudarikov et Kurotschkin, 1968 (Trematoda,Diplostomidae) in Rybinsk Reservoir

During a parasitological survey of nonnative fish species—rudd Scardinius erythrophthalmus—in the Rybinsk Reservoir, the metacercariae Ornithodiplostomum scardinii were found in its brain. This is the first find of this helminth in the Upper Volga basin. The rudd was infected with the prevalence 31.3%, with an intensity of 1–12 parasites per fish. Data on the current distribution of the trematode O. scardinii in the Volga River basin are provided.     

Poikilotherm vertebrate cell lines and viruses: A current listing for fishes

Summary A survey of the literature and of work being done in vertebrate cell culture shows that there are currently in existence and available to investigators some 61 cell lines representing 17 families and 36 species of fish. The literature of fish virology shows that at least 17 fish viruses have been isolated and that at least 15 others have been visualized by electron microscopy. A minimum of four major virus groups—rhabdovirus, orthomyxovirus, iridovirus and herpesvirus—are known from fish. Original references, key reviews and sources of cell lines are given.     

Food quality affects wing-form,demographic traits and number of yeast-like symbionts (YLS) in the planthopper vector,Delphacodes kuscheli (Hemiptera: Delphacidae)

Delphacodes kuscheli, the main vector of maize Mal de Río Cuarto disease in Argentina, was used to analyze the effect of food quality on wing-form, demographic traits and number of yeast-like symbionts (YLS). First instar nymphs were caged on the leaf apex or on the ligular zone of oat plants, characterized by having low and high nutritional value respectively, and followed in their development to adulthood. Food quality affected the proportion of wing morphs, with an increased number of brachypterous individuals on the higher food quality zone. Macropterous and brachypterous females from the ligular zone had higher survivorship, shorter development time and higher number of YLS. For males, development time and number of YLS did not differ significantly in individuals fed from both zones, while body and wing length were superior in individuals fed on the ligular zone. Results suggest that females allocate the resources from feeding on a richer zone to reduce the pre-reproductive period and to increase the number of YLS, and males acquire a larger size while maintaining development time and YLS number. This is the first study quantifying the variation of number of YLS according to food quality in a Neotropical planthopper pest.     

Reduction of Copper Ion Phytotoxicity Using Rhodococcus-Biosurfactants

Biology Bulletin - Abstract—The effect of copper on the germination of seeds of several agricultural crops, such as common vetch (Vicia saliva L.), white mustard (Sinapis alba L.), and...     

Cultural consonance and psychological distress: examining the associations in multiple cultural domains

Cultural consonance is the degree to which individuals, in their own beliefs and behaviors, approximate widely shared cultural models. In previous research in Brazil and the United States we found that higher cultural consonance in the cultural domains of lifestyle and social support was associated with lower psychological distress. The aim of this paper is to expand on these results in two ways. First, the measurement of cultural consonance has been improved through a closer link of cultural domain analyses and survey research. Second, the number of domains in which cultural consonance has been examined has been expanded to include—along with lifestyle and social support—family life, national identity, and food. We found that cultural consonance in these five domains can be conceptualized as two latent variables of generalized cultural consonance, and that this generalized cultural consonance is associated with lower psychological distress. These results continue to support the usefulness of cultural consonance as a theoretical construct in the explanation of human social suffering.