Morphological,Molecular and Pathological Characterization of Phytophthora amaranthi sp. nov. from Amaranth in Taiwan

In the spring of 2007, a serious disease on amaranth was noticed in several farms in the major amaranth production area in central Taiwan. Abundant oospores were found in the disease tissues. A species of Phytophthora was consistently isolated from disease tissues. The organism formed abundant oospores with smooth walls and with amphigynous antheridia in single culture. Sporangia were partially deciduous with short‐ to medium‐length pedicels. Morphological characteristics of this organism did not match any reported Phytophthora species, and the organism was named Phytophthora amaranthi. Pathogenicity tests and molecular characterization confirmed the identity of the organism as a new pathogen of amaranth and a new species of Phytophthora.     

Morphological and molecular characteristics of a species of Hepatozoon Miller, 1908 (Apicomplexa: Adeleorina) from the blood of Isoodon obesulus (Marsupialia: Peramelidae) in Western Australia

Examination of blood films as part of a study to assess the health status of the southern brown bandicoot Isoodon obesulus (Shaw) in Western Australia revealed the gamonts of a haemogregarine parasite in some samples, the first to be recognised in a bandicoot in this state. Light microscope morphological characteristics and partial sequence of the 18S rRNA gene were used to describe these organisms. Morphological characters did not differentiate the organism in the current study from previously reported Hepatozoon peramelis (Welsh & Dalyell, 1909). Phylogenetic analysis has not previously been reported for any species of Hepatozoon from Australian marsupials and consequently could not be used to confirm the identity of the organism in the current study as that described in the 1900s. If this organism is H. peramelis, then it has a wide distribution, being found in three species of bandicoot, in western and eastern Australia and the in island state of Tasmania.     

The association of Mycobacterium flavum 301 with gramnegative bacteria: ultrastructural and biochemical evidence

Morphological characteristics, respiratory quinones, biochemical activities, cell wall ultrastructure and DNA base composition of Mycobacterium flavum 301 were studied. On the basis of the composition of its cell wall, its respiratory quinone and ubiquinone, the organism was associated with gramnegative bacteria. The strain appears to represent a group of bacteria hitherto not described.     

Observations onCyanotheca longipes Pascher

Summary Morphological and cytological investigations conducted onCyanoiheca longipes Pascher, revealed the presence of a nucleus, and the asexual and sexual reproduction of the organism is described. It was found that the asexual reproduction is either a modified binary fission or by means of formation of numerous endospores. The sexual reproduction consists of pedogamy which takes place in the stalk.These observations excludeCyanotheca from the division of Cyanophyta.Some speculations about the systematic position of this microorganism are discussed without giving a definite answer about its correct place in the plant kingdom.     

A new actinomycete strain SK4-6 producing secondary metabolite effective against methicillin-resistant Staphylococcus aureus

A new actinomycete strain designated SK4-6, was isolated. This organism exhibited strong activity against bacteria including methicillin-resistant Staphylococcus aureus and Micrococcus luteus, in addition to the causative agents of Candidiasis and Aspergillosis diseases, Candida albicans and Aspergillus species respectively. Morphological and chemical studies indicated that this organism belongs to the genus Streptomyces. Analysis of the 16S rRNA sequence of strain SK4-6 showed a high similarity, 99%, with S. qinlingensis. Optimization of cultural conditions was carried out using Plackett–Burman statistical design where seven variables were examined. Starch, pH and inoculum size showed a positive effect on the production of the active substances, however, sucrose, (NH₄)₂SO₄ and yeast extract repress the production.     

Geographical variation in morphology and its environmental correlates in a widespread North American lizard,Anolis carolinensis (Squamata: Dactyloidae)

The green anole, Anolis carolinensis, has long been an important model organism for studies of physiology and behaviour, and recently became the first reptile to have its genome sequenced. With a large and environmentally heterogeneous distribution, especially in relation to well‐studied Antillean relatives, A. carolinensis is also emerging as an important organism for novel studies of geographical differentiation and adaptation. In the present study, we quantify the degree of morphological variation in this species and test for environmental correlates of this variation. We also examine adherence to Bergmann's and Allen's rule, two eco‐geographical principles that have been well studied over large species ranges. We sampled from 14 populations across the distribution of the species in North America and measured 28 distinct morphological traits. We also collected a suite of environmental variables for each site, including those related to temperature, precipitation, and vegetation. Ultimately, we found a large degree of geographical variation in morphology, with head traits contributing the most to differences among populations. Morphological variation was correlated with variation in temperature, precipitation, and latitude across sites. We found no support for reverse Bergmann's rule typical of squamates, although we did find a trend of reverse Allen's rule. Ultimately, the present study provides a novel look at A. carolinensis and establishes it as a strong candidate for further studies of variation and adaptation over a large range.     

Geographic variation in lower pharyngeal jaw morphology in the Shiner Perch <Emphasis Type="Italic">Cymatogaster aggregata</Emphasis> (Embiotocidae,Teleostei)

Correlations of feeding morphology with body morphology reflect ecological variation of a species and the geographic or ontogenetic scales over which it occurs. In this study, evidence was found for geographic variation in lower pharyngeal jaw (LPJ) morphology of Cymatogaster aggregata Gibbons (Embiotocidae, Teleostei) in the Pacific Northwest, U.S.A. Correlations of LPJ morphology with body morphology were more obvious in adulthood than the juvenile stage. Morphological patterns corresponded better with environmental variables and gut contents than geographic proximity, indicating that they were most likely caused by habitat differences. Qualitative common garden experiments indicated the nature and direction of plastic responses, and indicate a likely plastic origin to most naturally observed differences. Recognizing ecological patterns via morphology is an important first step in understanding how and when ecological mechanisms influence the functional role of an organism within its environment.     

Studies on species of Conidiobolus from India-V

Summary Morphological and cultural studies on two new species ofConidiobolus isolated from plant detritus in India are described.C. terrestris is characterized by mycelium differentiating into chains of hyphal bodies, which in older cultures become thick-walled. The morphological similarity of the fungus to the causal organism of Jorge Lobo's disease in Surinam incited byLoboa loboi and the possibility of that being a species ofConidiobolus are discussed.C. lichenicola isolated from decaying lichens is characterized by a vegetative thallus composed of sinuous, lobate and compacted coralloid mycelial mass. The conidial germination is characteristic and organises the coralloid thallus from the very initial stages.     

Characteristics of an Organism Causing Spoilage in an Orange Juice Beverage

S ummary . An organism causing an off-flavour in an orange juice drink is described. Morphological and biochemical properties of this organism, which produces a characteristic coral pink growth on most media, are also reported. Possible relationships with similar organisms known to occur in fruit juices and on fruits are discussed.     

In vivo observation of metamorphosis of Plodia interpunctella Hübner using three‐dimensional optical coherence tomography

Morphological assessment and three‐dimensional reconstructions of internal structures of Plodia interpunctella Hübner during metamorphosis stages were experimentally demonstrated using optical coherence tomography (OCT) for the first time. The conventional, complex sectioning methods were significantly simplified owing to the non‐invasive three‐dimensional imaging capability of OCT. Further, this study demonstrates the use of OCT as a non‐invasive detection tool for in vivo morphological observation of metamorphosis stages to gain a better understanding about the growth of internal organs, which can be considered a useful discovery in the field of entomology. Thus, the metamorphosis stages starting from the larva, three pupa stages to the adult stage were periodically visualized to examine the development of internal organs at each specific stage. This study essentially offers real‐time morphological information by non‐destructive observation of the organism and can also be useful for the investigation of other agricultural pests.     

Differentiation and speciation in mountain streams: a case study in the caddisfly Rhyacophila aquitanica (Trichoptera)

Few studies have analysed the biogeography of mountain aquatic organisms, although this habitat provides stable conditions in which many species survived Pleistocene climatic oscillations, usually in the geographical vicinity of their present distribution ranges. The mountain caddisfly Rhyacophila aquitanica was selected as a model organism for this habitat type. Morphological measurements of genitalia and external characters of male individuals were obtained from almost the entire range of distribution of the species. Morphometric results were analysed by cluster analysis and multivariate statistics. Important differences were discovered among three population groups of R. aquitanica inhabiting different European mountain ranges: (i) mountain ranges north‐west of the Alps (Massif Central, Vosges, Schwarzwald and Fribourg); (ii) the southern Alps (Lombardia and Carinthia); and (iii) the western part of the southern Carpathians. This divergence suggests a long‐term isolation among these groups, which presumably took place long before the last Pleistocene glaciation, with no secondary contact among these populations. The differentiation centres of the southern Alps and Carpathian groups may have been mostly homotopic to their actual ranges, whereas the western group must have been distributed in the areas west or north‐west of the Alps with secondary expansions and disjunctions.     

Phyllody Disease of Crotalaria saltiana in the Sudan: Transmission to Catharanthus roseus and Detection of MLOs by Fluorescence and Electron Microscopy

Phyllody disease of Crotalaria saltiana Andr. first noted in the Sudan in 1962, was recently observed in many localities in the Gezira province in the central region of the country. Diseased plants generally exhibited stunting and excessive proliteration of lateral shoots (witches' broom growth) with small and chlorotic leaves. Morphological transformations of flowers were the most striking symptoms. Floral segments showed various stages of virescence and phyllody as a part of a complete transformation of floral buds into leafy branches. The Crotalaria phyllody agent was transmitted by grafting to faba bean (Vicia faba L.) and with dodder from the latter to periwinkle (Catharanthus roseus). The symptoms reproduced in C. roseus resembled those induced in it by the faba bean phyllody MLO (mycoplasma-like organism), suggesting a close relationship between the two agents. Fluorescence and electron microscopy were used to detect and characterize MLO in diseased plants. Fluorescence reactions in sieve tube elements were observed in sections stained with the DNA-binding fluorochrome Bisbenzimid H 33258. Electron microscope observations in corresponding zones permitted the visualization of wall-less pleiomorphic MLOs confined to sieve tube elements of the phloem tissues of diseased plants.     

Slime travelers: Early evidence of animal mobility and feeding in an organic mat world

Mobility represents a key innovation in the evolution of complex animal life. The ability to move allows for the exploration of new food sources, escapes from unfavorable environmental conditions, enhanced ability to exchange genetic material, and is one of the major reasons for the diversity and success of animal life today. The oldest widely accepted trace fossils of animal mobility are found in Ediacaran‐aged rocks (635–539 Ma). The earliest definitive evidence for movement associated with exploitation of resources for feeding occurs in the White Sea assemblage of the Ediacara Biota—macroscopic, soft‐bodied fossils of Ediacaran age. Here, we evaluate potential support for mobility in dickinsoniomorphs, presenting new data regarding abundant Dickinsonia and associated trace fossils from the Ediacara Member, South Australia. Results quantitatively demonstrate that Dickinsonia was capable of mobility on relatively short, ecological timescales. This organism was bilaterally symmetrical, likely moved via muscular peristalsis, and left trace fossils due to active removal of the organic mat related to feeding. Analogous structures associated with Yorgia indicate that it was also mobile and fed in a similar manner. Morphological evidence suggests that two other modular taxa, Andiva and Spriggina, were able to move but did not feed in a manner that impacted the organic mat. Together, these data suggest that mobility was present in multiple disparate bilaterally symmetrical Ediacaran taxa.     

Size correction in biology: how reliable are approaches based on (common) principal component analysis?

Morphological traits typically scale with the overall body size of an organism. A meaningful comparison of trait values among individuals or populations that differ in size therefore requires size correction. A frequently applied size correction method involves subjecting the set of n morphological traits of interest to (common) principal component analysis [(C)PCA], and treating the first principal component [(C)PC1] as a latent size variable. The remaining variation (PC2–PCn) is considered size-independent and interpreted biologically. I here analyze simulated data and natural datasets to demonstrate that this (C)PCA-based size correction generates systematic statistical artifacts. Artifacts arise even when all traits are tightly correlated with overall size, and they are particularly strong when the magnitude of variance is heterogeneous among the traits, and when the traits under study are few. (C)PCA-based approaches are therefore inappropriate for size correction and should be abandoned in favor of methods using univariate general linear models with an adequate independent body size metric as covariate. As I demonstrate, (C)PC1 extracted from a subset of traits, not themselves subjected to size correction, can provide such a size metric.     

Investigation of the lytic ability of South African bacteriophages specific for Staphylococcus aureus,associated with bovine mastitis

Bovine mastitis is an infectious disease of the mammary glands of dairy cattle primarily causaled by the bacterium, Staphylococcus aureus subsp. aureus Rosenbach1884. Traditional control of this organism was through the use of antibiotics. However, S. aureus is developing resistance towards these chemotherapeutic agents faster than they are being developed. Bacteriophages can serve as an alternative control measure for the disease. This study investigated the prevalence of phages and S. aureus within the South African dairy environment, as well as infectivity of phage isolates against antibiotic-resistant S. aureus. The four S. aureus strains used in the study displayed resistance to representative antibiotics from both the β-lactamases and non-β-lactamases, macrolides, aminoglycosides and glycopeptides. Susceptibility was only noted towards the tetracycline antibiotics. Twenty-eight phages were isolated and screened against four strains of S. aureus. Only six phages showed biocontrol potential based on their wide host range, high titres and common growth requirements. Morphological and preliminary genomic analysis was carried out on the three best performing phages. At an optimal titre of between 6.2 × 10⁷ and 2.9 × 10⁸ pfu.ml^?1, the phages were able to reduce live bacterial cell counts between 64% and 95%. In addition, these six phages showed further infectivity towards S. aureus strains that were isolated from different milk-producing regions during a farm survey. The phages isolated in this study show reasonable potential for in vivo applications.     

Physiological properties,conjugation and taxonomy ofCephaloascus fragrans Hanawa 1920 (syn:Ascocybe grovesii Wells 1954)

Summary It has been established that the type cultures ofCephaloascus fragrans Hanawa 1920,Ascocybe grovesii Wells 1954 and a culture isolated from oakwood from Japan are identical. Conjugation in this organism has been observed. The taxonomic position of this organism in theAscomycetes was discussed. If this organism is incorporated in the classification ofLodder andKreger-van Rij, it seems justified by taxonomical reasons to create a new subfamily: theCephaloascoideae.     

Contamination of a hospital environment byClostridium difficile

Clostridium difficile was recovered from a variety of environmental sites in three hospital rooms occupied by a patient who had colitis due to this organism.C. difficile was detected for 40 days after the patient was moved from one of these rooms. These findings suggest that the contaminated hospital environment may be a clinically significant reservoir forC. difficile and that this organism may be a nosocomial pathogen. Isolation of patients and adequate decontamination of rooms may be needed to minimize risk to other patients.     

Linear growth and lipid synthesis in the oleaginous yeastRhodotorula gracilis

A kinetic analysis was made of batch cultures of an industrially important yeastRhodotorula gracilis, using a nitrogen-limited medium. The exponential phase of growth lasted 15 h, followed by a linear phase up to 36 h. The generation time was 2.8 h (15–36 h of fermentation) which corresponded to a μ of 0.248/h. The lipid synthesis was partially growth-associated with the linear growth phase (15–36 h) and the early stationary phase (36–60 h). The rate of linear growth was estimated as 0.267 g cell per L per h and the rate for lipid synthesis over the period of 15–60 h was 0.17 g lipid per L per h. More than 50% of the total supplied nitrogen was assimilated by the organism and the rest remained in the medium. Sugar assimilation was nearly 100% by the end of 60-h fermentation. At 0 h the intracellular protein was 3.3% and it significantly increased to 11.7% by the end of 12 h. Morphological and physiological characteristics were also found to change during different stages of growth.