Colony Margin Research Articles

Fracking the Glacier: From mimicry to hybridization of professional accountantCanadian field

In this study we draw on postcolonial theory to examine how some professionals from “diverse” backgrounds are able to overcome systemic barriers and to theorize how the success of some individuals, over time, disrupts the reproduction of both discursive and material structures that legitimize and maintain exclusion. We examine how situating migrant accounting professionals in their bodies, as well as in temporal context, provides new insights that help to explain how exclusion operates within a professional field but also, how the agency of individuals evolves over time and has longer term implications for subsequent generations of professionals. Using post-colonial analysis of the narratives of twenty four accountants migrating to Canada, we show how early migrants from the colonial margins initially confront significant barriers that force them to mimic the performances of Canadian accountants in order to re-constitute their professional identities in Canada. However, over time, as early arriving migrant accountants re-establish their professional identities, they both actively and passively facilitate entry for subsequent arrivals. We argue that this is accomplished through disrupting the routine reproduction of the seemingly natural professional identity and social structure and through the iterative hybridization of the relatively homogeneous professional identity that has dominated the Canadian profession for over a century.

PilG is Involved in the Regulation of Twitching Motility and Antifungal Antibiotic Biosynthesis in the Biological Control Agent Lysobacter enzymogenes.

Lysobacter enzymogenes strain C3 is a gliding bacterium which produces the antifungal secondary metabolite heat-stable antifungal factor (HSAF) and type IV pilus (T4P) as important mechanisms in biological control activity against fungal pathogens. To date, the regulators that control HSAF biosynthesis and T4P-dependent twitching motility in L. enzymogenes are poorly explored. In the present study, we addressed the role of pilG in the regulation of these two traits in L. enzymogenes. PilG of L. enzymogenes was found to be a response regulator, commonly known as a component of a two-component transduction system. Mutation of pilG in strain C3 abolished its ability to display spreading colony phenotype and cell movement at the colony margin, which is indicative of twitching motility; hence, PilG positively regulates twitching motility in L. enzymogenes. Mutation of pilG also enhanced HSAF production and the transcription of its key biosynthetic gene hsaf pks/nrps, suggesting that PilG plays a negative regulatory role in HSAF biosynthesis. This finding represents the first demonstration of the regulator PilG having a role in secondary metabolite biosynthesis in bacteria. Collectively, our results suggest that key ecological functions (HSAF production and twitching motility) in L. enzymogenes strain C3 are regulated in opposite directions by the same regulatory protein, PilG.

Mutabilis in mutabili: Spatiotemporal dynamics of a truffle colony in soil

The functioning of ectomycorrhizal (ECM) symbioses is closely related to the development of the soil mycelial phase the ECM fungi. The properties and spatiotemporal dynamics of such mycelia in ecosystems is, however, poorly understood. Here we show, using a soil colony of summer truffle (Tuber aestivum) as a model, that an ECM mycelium may only grow and colonize newly-opened soil patches when soil temperatures rise above certain threshold, in this case +10 °C, provided other requirements such as sufficient soil moisture are fulfilled. Extension rates of truffle mycelium in the fields was recorded as >0.3 μm min−1, several-fold greater than that predicted from laboratory cultures. Further, we demonstrated that there was a consistent spatial differentiation in mycelium growth patterns within the fungal colony on a decimeter scale, changing from “diffusion” type of growth at the colony margin to “colony-front” pattern further away from the colony margin. This change was clearly accompanied by shifting structure of soil microbial communities with Terrimonas sp. and another unidentified bacterium correlating with the “colony-front” mycelium growth pattern, and Sphingomonas sp. and Lysobacter brunnescens with the “diffusion” type of mycelium growth. Possible implications of the observed truffle colony differentiation are discussed for processes like fruit-body formation and dispersal of this ECM fungus. Our data indicate that the thallus of T. aestivum has to be considered as a principally variable (“mutabilis”) being in space and time, whose behavior correlates with conditions in ever changing soil environment (“in mutabili”).

Black pod disease on cacao (Theobroma cacao, L) in Ghana: Spread of Phytophthora megakarya and role of economic plants in the disease epidemiology

To implement management strategies of Phytophthora pod rot (black pod) diseases successfully, knowledge of the role of economic plants, and the diversity and distribution of Phytophthora species on these plants in the cacao ecosystem is essential. In this study, the spread of Phytophthora megakarya in the cocoa growing districts of Ghana was monitored through annual surveys from 1985 to 2012. In addition, from July to October, 2008, Phytophthora was isolated from randomly collected non-symptomatic rootlets of economic plants on cacao farms and from symptomatic pods and stems of cacao from 139 locations in 22 districts in the cacao growing regions. A total of 1459 Phytophthora isolates from 22 plant species belonging to 19 families were characterized. The Phytophthora isolates showed six different morphological patterns on Campbell Vegetable Juice Agar medium. The patterns were variable stellate striate, cotton wool-like, deep cotton wool-like only at colony margin, light cotton wool-like pattern only at colony margin, and dense aerial, fluffy colonies without pattern. However, microscopic examination of the sporangia of the isolates revealed only two species, Phytophthora palmivora and P. megakarya. P. megakarya was found to have spread from Akomadan and Bechem in 1985 to 50 more administrative districts in 2012. This study also represents the first report of isolation of P. megakarya from Xanthosoma saggitifolium, Musa paradisiaca, Elaeis guinnensis, Persea americana, Carica papaya, Mangifera indica, Colocasia esculenta, Athyrium nipponicum and Ananas comosus on cacao farms in Ghana. The fact that economic plants on cacao farms harbour Phytophthora species may explain the failure to obtain appreciable control of Phytophthora diseases as the current management of these diseases is mainly targeted at the host crop, Theobroma cacao.

Evaluation of Culture Media for Growth Characteristics of Alternaria solani, Causing Early Blight of Tomato

Early blight is most common and devastating disease in tomato plant caused by deuteromycotina fungi, Alternaria solani. This fungus grows well in potato dextrose agar and Richard’s broth medium in vitro. The growth of the fungi were tested under culture in twelve different liquid and solid media and compared with each other. Potato dextrose agar and oat meal agar among solid media and Richard’s broth and Sabouraud’s broth among liquid media appeared to be better than other media for growth of tomato early blight causing fungi. The growth characteristics such as color of colony and substrate, margin of colony, topography of mycelium along with the sporulation of the test fungus were studied on these solid media. Fungus sporulation was best in oat meal agar media. Maximum growth of the fungus was observed at 8 days after inoculation with continuous increasing growth in the potato dextrose broth (PDB) medium, although growth rate was decreasing after the 2 days of inoculation. This study will be helpful for further investigations on the physiology of the fungus and management of the disease. This investigation may be useful for taxonomic study of the fungus.

First Report of Asiatic Brown Rot Caused by Monilinia polystroma on Peach in Italy.

Monilinia spp. are well-known pathogens causing brown rot of fruit trees in many fruit production areas worldwide. In Italy, three Monilinia species are particularly significant with regard to fruit trees, causing blossom and twig blight and brown rot in fruits: Monilinia laxa (Aderhold and Ruhland) Honey, M. fructicola (Winter) Honey, and M. fructigena (Aderhold and Ruhland). In 2009, a new species, M. polystroma, was distinguished from M. fructigena based on morphological and molecular characteristics in Europe (3). M. polystroma is not known to occur in Italy and to date has been reported from the Czech Republic (1), Hungary (3), Poland (4), Serbia (5), and Switzerland (2). In July 2013, during a survey for fungal postharvest pathogens, stored peaches (Prunus persica (L.) Batsch) belonging to different cultivars showing brown rot symptoms were observed in the Emilia Romagna and Sardinia regions of Italy. Typical decay spots were circular and brown, tending toward black, and 5% of peaches presented a large number of yellowish or buff-colored stromata and firm decayed tissues, the symptoms originated by M. polystroma. The pathogen was isolated on V8 agar (V8A) and culture plates were incubated at 25°C in darkness for 5 days. A conidial suspension was spread on malt extract agar (MEA) and single spores were selected. M. polystroma colonies grown on potato dexstrose agar (PDA) were yellowish in color. Irregular black stromatal crusts occurred on the edges of the colonies after 10 to 12 days of incubation and on the margin was present sporogenous tissue slightly elevated above the colony surface, color buff/pale luteous (1). The conidia were one-celled, ovoid or limoniform, smooth and hyaline, and 12 to 20 × 8 to 12 μm in distilled water when grown on V8A at 22°C. The ribosomal ITS1-5.8S-ITS2 region was PCR-amplified from genomic DNA obtained from mycelium using primers ITS1 and ITS4. A BLAST search in GenBank revealed the highest similarity (99%) to M. polystroma sequences (GenBank Accession No. GU067539). Pathogenicity was confirmed using surface-sterilized mature 'Red Heaven' peaches. The fruits were wounded (2 × 2 × 2 mm) twice with a sterile needle and inoculated with 2-mm plugs of 7-day-old mycelia from fungal colony margins. The sample unit was represented by 10 fruits. Control fruits were inoculated with PDA. After 7 days of incubation at 20°C in plastic containers with high humidity, typical symptoms of brown rot developed on both the wounds of all inoculated fruits, while control fruits remained symptomless. By the 14th day, all fruits had rotted and the yellowish exogenous stromata appeared on the surface of infected peaches. The fungus isolated from inoculated fruit exhibited the same morphological and molecular features of the original isolates; the molecular analysis performed using the primers by Petroczy (3) confirmed the result of the PCR with ITS1 and ITS4 primers. To our knowledge, this is the first report of M. polystroma on peach in Italy. This is relevant because the new pathogen could spread into other European countries that are main peach producers (such as Spain), causing economic losses. Bringing it to the attention of the scientific community allows the arrangement of research studies for assessing potential resistances with a significant impact on disease control management. Further studies are necessary to determine geographic distribution, prevalence, and economic importance of this organism in Italy.

English

Due to premature defoliation, early blight epidemics can cause major yield losses. Large-spore Alternaria species such as A. solani and A. tomatophila have long been recognized as important pathogens responsible for such blight disease in the family Solanaceae and thus represent a serious risk for crop production. Small-spore Alternaria species have also been frequently isolated from plant samples with typical blight symptoms but their incidence as primary pathogens is often controversial. In order to study the diversity of small-spore Alternaria species, 32 isolates were selected from a larger collection of 130 isolates from infected leaves, fruits and stems of tomato from various growing regions of North-West Algeria. Morphological characterization under standard conditions and polymerase chain reaction (PCR) analyses using specific primers to amplify a part of the ITS regions and the 5.8S gene were conducted to confirm their identification as members of the alternata section. They were then examined according to morphological characteristics of conidia and sporulation patterns on potato carrot agar (PCA) and were segregated into three morphological species: A. alternata, A. tenuissima and A. arborescens. Colony type, substrate colour, margin, zonation, pigmentation, colony diameter and conidia production were studied on potato sucrose agar (PSA). Physiological parameters and nutritional requirements of the isolates were also assessed and a data matrix based on cluster analysis and Euclidean distance was constructed. Results of pathogenicity test on tomato showed obvious diversity among the isolates and they could be separated into two groups based on their virulence. The dendrogram based on the influence of cultural, nutritional and physiological characters suggests moderate heterogeneity within the populations of A. alternata and A. tenuissima. The small-spore species formed five clusters that fundamentally paralleled the morphological groupings. However, the results provided no evidence for geographical and pathogenicity clustering of isolates. Key words: Epidemiology, Solanaceae, small-spore Alternaria species, pathogenic variability, cultural characters, physiological diversity.

Isolation and Characterization of Bacteria from Coal Mines of Dara Adam Khel, Pakistan

The coal fields of Pakistan and their microbiology have not been fully explored. Therefore, a study was conducted on the coal mines of Dara Adam Khel located in the Federally Administered Tribal Areas of Pakistan. For this purpose, sampling was done from nine different mines with varying depths. A total of 32 bacterial strains were isolated and their colony size, form, texture, color, margin, elevation and opacity were noted. The majority of the strains (75%) were found Gram negative. The bacterial strains were then characterized in detail by different biochemical tests including catalase, citrate, oxidase, indole, triple sugar iron, motility, methyl red-Vogues Proskeur, nitrate reduction and phenylalanine deaminase, and an enormous physiological diversity was observed. The Gram positive strains were further characterized on molecular level using 16S rRNA gene amplification and sequence analysis. Based on molecular analysis, seven strains were identified as Bacillus tequilensis, B. cereus, Janibacter melonis, Kocuria atrinae, B. anthracis, K. rosea and B. simplex. The other two strains (strains 6 and 41) had molecular similarity of only 98% and 97% with Brachybacterium spp. and Arthrobacter spp. respectively. The phylogenetic analysis further suggested that the strains 6 and 41 may be potential candidates for novel species; however, further work is needed for confirmation.

First Report of Brown Rot (Monilinia fructicola) on the Dogwood, Cornelian Cherry (Cornus mas).

Cornelian cherries (Cornus mas), also called cornels, are members of the dogwood family (Cornaceae), and are not true cherries. Cornelian cherry is primarily grown as an edible landscape ornamental in the United States. Brown rot, caused by fungi in the genus Monilinia, is one of the most important diseases of stone fruit worldwide. In the United States, M. fructicola is the most commonly observed Monilina species, although M. fructigena and the European brown rot pathogen, M. laxa, may also infect stone fruit. M. fructigena is the only Monilinia species reported to infect cornelian cherry, but there is only a single report of it occurring in the United States (1,4). All three species have similar morphology and are commonly misidentified (1,3,4). In August of 2010 and 2013, in one location, brown rot was observed on fruit of the cornelian cherry cultivar Elegans. In both instances, only 'Elegans' fruit was infected while neighboring 'Sunrise' exhibited no symptoms in the field, and lesions did not appear to develop into shoot blight. In 2013, single-spore isolates from the diseased fruit were cultured on potato dextrose agar (PDA) incubated at 25°C for 5 days. Colony morphology was consistent with M. fructicola and was rapidly growing, gray, producing concentric rings, and developing smooth colony margins. Conidia were hyaline, 10 × 15 μm, and formed in branched, monilioid chains of varying lengths (1). Molecular-based species identification was performed on the 450-bp amplified ribosomal internal transcribed spacer (ITS) sequences, using primers ITS1 and ITS4. BLAST searches of the ITS sequences in GenBank showed the highest similarity (100%) with sequences of M. fructicola isolates from Italy (FJ411110), China (FJ515894), and Spain (EF207423). Pathogenicity was confirmed by inoculating surface-sterilized, mature 'Sunrise' fruit with mycelial plugs of the isolate identified with the ITS sequence. Mycelial plugs (3 mm in diameter) were removed from the periphery of a 5-day-old colony and placed upside down into five fruit that were wound-inoculated with a 3-mm cork borer, petiole hole-end inoculated, or unwounded but inoculated; control fruit for each treatment received sterile plugs of PDA as a control. All fruit was stored in a moist chamber for the duration of the experiment. Wound-inoculated fruit developed symptoms within 2 days; sporulating lesions developed within 5 days. Symptoms of infection via the petiole developed in 4 days; by day six, three of the five inoculated fruit were infected, and four of the five were infected by day eight. Unwounded, inoculated fruit showed symptoms on day six; three of the five fruit were infected by day eight. None of the control inoculations showed Monilinia infection. Pathogens were re-isolated from the inoculated fruit and confirmed to be M. fructicola on the basis of morphological characteristics. To our knowledge, this is the first fulfillment of Koch's postulates demonstrating that M. fructicola can infect cornelian cherry. A previous report by Höhnel in 1918 described infection by Lambertella corni-mas of a cornelian cherry in Austria; however, the taxonomic details presented are consistent with M. fructigena (2).

First Report of Sclerotinia minor on Brassica rapa subsp. pekinensis in Central China.

Chinese cabbage (Brassica rapa subsp. pekinensis Hanelt) is a leafy vegetable widely grown in China. In December 2012 to March 2013, a leaf rot disease was observed on the lower part of cabbage leaves in a field in Xianning, Hubei Province, China, with the incidence of 6.3% in that field. The diseased leaves showed water-soaked rot and brown symptoms at the top surface. White fluffy mycelia and small black sclerotia were produced on the lesion surface. Cabbage leaf tissues from the disease/healthy-bordering areas and the sclerotia from the lesions were separately surface-sterilized in 75% ethanol (v/v) for 30 s, followed by rinsing three times in sterilized water. The surface-sterilized tissues and sclerotia were placed on potato dextrose agar (PDA) and incubated at 22°C. Individual emerging fungal colonies from the leaf tissue pieces and the sclerotia were transferred to new 9-cm-diameter PDA plates and incubated for 15 days. A total of 40 isolates (20 from diseased tissue and 20 from sclerotia) were obtained. All the isolates grew rapidly on PDA with an average growth rate of 2.2 cm/day and produced abundant sclerotia on the colony surface (1,179 sclerotia/plate on average). None of the isolates produced conidia and any other spores in the PDA cultures. Mature sclerotia were black, irregular, spherical or elliptical, had a diameter of 0.5 to 1 mm, and easily detached from the colonies. The cultural and morphological characteristics of the isolates matched the description for Sclerotinia minor Jagger (3). Two isolates, A1 (from leaf tissue) and S2 (from a sclerotium), were further identified by analysis of the ITS region (ITS1-5.8S rDNA-ITS2) using the primer pair ITS1/ITS4. The resulting 540-bp DNA sequences (GenBank Accession Nos. KC836493 for A1 and KC836494 for S2) shared 100% identity S. minor isolate 62907 (JF279880). Pathogenicity of the isolates A1 and S2 was tested by inoculating detached cabbage leaves with mycelial agar plugs removed from the colony margin of the 3-day-old cultures. Isolates A1 and S2 were each inoculated on three leaves with three plugs per leaf. Three cabbage leaves inoculated with PDA plugs were treated as a control. The treated leaves were covered with plastic films to maintain high humidity (>90% RH) and incubated at 22°C for 72 h under the regime of 12 h light/12 h dark. Results showed that while the control leaves remained healthy, brown and water-soaked lesions appeared around the mycelial agar plugs of each isolate. Average lesion diameters were 47.5 mm for A1 and 47.8 mm for S2. Abundant small sclerotia were produced on necrotic leaf lesions after 7 days. The fungus in diseased leaf tissues was re-isolated and the morphological characteristics of the resulting fungus were the same as S. minor isolated from infected field-grown cabbages. Therefore, S. minor is the causal agent for the leaf rot disease on Chinese cabbage. S. minor has been reported to infect a few plant species in the genus Brassica, including B. rapa subsp. oleifera (3), B. oleracea var. gemmifera (3), B. napus (2), B. oleracea var. capitata (3), B. oleracea var. botrytis (3), and B. rapa (3). It was found on B. rapa subsp. pekinensis in Korea (1). To our knowledge, this is the first report of S. minor on B. rapa subsp. pekinensis in China.

First Report of Diaporthe neoviticola Associated with Wood Cankers of Grapevine in Turkey.

In recent years, delayed bud bursting, cane bleaching, shoot dieback, and cankers in 1-year-old canes and perennial arms were observed in vineyards of the Aegean region (western Turkey). These symptoms were frequently observed on the following major table grape (Vitis vinifera) cultivars: 'Alphonse Lavallée,' 'Cardinal,' 'Sultana Seedless,' and 'Trakya Ilkeren' in 2012. To determine the causal agents, symptomatic woody tissues (0.5 cm2) were sampled from the canes of nine Manisa and four Salihli Cities (13 total) grapevine varieties and were plated onto potato dextrose agar amended with tetracycline (0.01%) (PDA-tet). A considerable amount of phomopsis-like fungi were isolated from the symptomatic tissues and fungal colonies were incubated for 2 to 3 weeks to induce sporulation. After incubation for 14 days at 24°C in the dark, white mycelial growth with undulating colony margins, and abundant pycnidia producing hyaline, ellipsoidal, fusoid α-conidia with invisible nuclei, and β-conidia, were observed on PDA, and they resembled species in the Diaporthaceae (1,2). The α-conidia dimensions were 9.3 to 10.2 × 1.9 to 2.9 μm (avg. 9.7 × 2.4 μm) and β-conidia were 19 to 24 × 0.5 to 1 μm (avg. 22 × 0.9 μm). For molecular identification, fungal DNA was extracted from mycelial mats and ribosomal DNA fragments (ITS1, 5.8S ITS2 rDNA, amplified with ITS4 and ITS5 primers) (3) were sequenced and the sequences were compared with those deposited in NCBI GenBank in a BLASTn search. The representative isolate (MBAi43AG) showed 99% homology with Diaporthe neoviticola isolate from New Zealand KC145831.1. The DNA sequence of the identified isolate was submitted to GenBank under accession number KF460427. Pathogenicity tests were conducted under controlled conditions (24°C, 16/8 h day/night, and 70% RH) on 1-cm-diameter, detached green grapevine cv. Cabernet Sauvignon canes (with leaves) using the isolate of D. neoviticola specified above. The shoots were wounded by creating a 5-mm-diameter incision with a sterile scalpel. An agar disc with mycelia and pycniospores was placed into each wound and covered with Parafilm. Sterile PDA plugs were used as mock inoculum for the control plants. There were 10 replicates per treatment and the experiment was repeated twice. After 1 month of incubation, the green shoots were examined for the extent of superficial blackish lesions. The average lesion length on inoculated shoots was 18.2 mm for D. neoviticola. No lesions were observed in the control shoots. The fungal isolate was successfully re-isolated from 96% of inoculated shoots to fulfill Koch's postulates. To our knowledge, this is the first report of D. neoviticola causing wood canker and dieback of shoots on grapevine in Turkey.

Seaweed-Coral Interactions: Variance in Seaweed Allelopathy, Coral Susceptibility, and Potential Effects on Coral Resilience

Tropical reefs are in global decline with seaweeds commonly replacing corals. Negative associations between macroalgae and corals are well documented, but the mechanisms involved, the dynamics of the interactions, and variance in effects of different macroalgal-coral pairings are poorly investigated. We assessed the frequency, magnitude, and dynamics of macroalgal-coral competition involving allelopathic and non-allelopathic macroalgae on three, spatially grouped pairs of no-take Marine Protected Areas (MPAs) and non-MPAs in Fiji. In non-MPAs, biomass of herbivorous fishes was 70–80% lower, macroalgal cover 4–9 fold higher, macroalgal-coral contacts 5–15 fold more frequent and 23–67 fold more extensive (measured as % of colony margin contacted by macroalgae), and coral cover 51–68% lower than in MPAs. Coral contacts with allelopathic macroalgae occurred less frequently than expected by chance across all sites, while contact with non-allelopathic macroalgae tended to occur more frequently than expected. Transplants of allelopathic macroalgae (Chlorodesmis fastigiata and Galaxaura filamentosa) against coral edges inflicted damage to Acropora aspera and Pocillopora damicornis more rapidly and extensively than to Porites cylindrica and Porites lobata, which appeared more resistant to these macroalgae. Montipora digitata experienced intermediate damage. Extent of damage from macroalgal contact was independent of coral colony size for each of the 10 macroalgal-coral pairings we established. When natural contacts with Galaxaura filamentosa were removed in the field, recovery was rapid for Porites lobata, but Pocillopora damicornis did not recover and damage continued to expand. As macroalgae increase on overfished tropical reefs, allelopathy could produce feedbacks that suppress coral resilience, prevent coral recovery, and promote the stability of algal beds in habitats previously available to corals.

Fusarium solani and Fusarium oxysporum Associated with Root Rot of Glycyrrhiza uralensis in China

Liquorice (root of Glycyrrhiza uralensis Fisch.) is an important Chinese traditional medicine for many ailments (4). From 2002, severe outbreaks of root rot occurring on cultivated G. uralensis plants in Ningxia, China, have affected the yield and quality of liquorice and been considered as a major threat to commercial production of liquorice. Approximately 30% of the plants die from this disease in Ningxia every year. The disease, mainly affecting 2- to 4-year-old G. uralensis seedlings, begins with brown rot of root tips or lateral roots followed by internal decay of taproots during June to August every year. The infected plants are wilted with chlorotic foliage and easily pulled up from the soil. Root rot is clearly visible as a severe brown discoloration of vascular tissue along taproots. In severe cases, white mycelia are clearly visible on the surface of diseased roots and roots are decomposed. Isolations from diseased roots were made on potato dextrose agar (PDA) amended with streptomycin sulfate. Isolates (n = 78) were recovered from symptomatic roots (n = 105) and pure cultures were established by the single spore method. The two most frequently isolated fungi were transferred to potato sucrose agar and identified as Fusarium solani (61.5%) and F. oxysporum (30.8%) (1). The monophialides bearing microconidia of F. solani are long when compared to those of F. oxysporum. Genomic DNA of strains F. solani G013 and F. oxysporum FLR were extracted from mycelia with the cetyltrimethylammonium bromide (CTAB) method. Primers EF1-728F and EF1-986R were used to amplify the translation elongation factor-1α (TEF-1α) gene (2). The TEF-1α sequences of F. solani G013 (GenBank Accession No. AB777258) and F. oxysporum FLR (AB777257) shared 99 and 100% similarity with F. solani isolate NRRL52790 and F. oxysporum isolate NRRL 38328, respectively. Pathogenicity tests with one representative isolate of each species were conducted in the greenhouse on 1-month-old potted G. uralensis seedlings (12 plants per treatment). Isolates of the tested fungi were transferred to PDA and incubated in darkness at 24 ± 1°C for 7 days. Plant taproots about 5 cm below the soil surface were wounded with a sterile needle and five 5-mm-diameter fungal disks on the margin of colony were taken and firmly placed on the wounded location of each taproot with tinfoil; wounded taproots of seedlings inoculated with sterile PDA disks were used as controls (3). Root rot was assessed 2 months after inoculation. F. solani G013 and F. oxysporum FLR produced root rot symptoms on inoculated plants that were the same as those observed in field plants, and the fungi were reisolated from roots with typical symptoms. Control plants inoculated with sterile PDA disks remained asymptomatic, and no pathogen was isolated from them. To our knowledge, this is the first report of root rot caused by F. solani and F. oxysporum on G. uralensis in China. Effective control strategies are needed to minimize losses.

Children's school reading and curriculum innovation at the edge of Empire

Purpose– Using the example of a “school paper” titledThe Children's Hour, developed in South Australia in the late nineteenth century, the purpose of this paper is to show the way that the colonial margins could act as sites of innovation in curriculum and pedagogy and not just as importers of ideas from the imperial centre.Design/methodology/approach– The analysis on which the examination ofThe Children's Houris based is a combination of Foucaultian discourse analysis and a genealogical approach to curriculum history which tracks different formations of techniques and programmes for shaping the human subject.Findings–The Children's Hour(1889-1963), featured the innovative use of literature and other genres, and provided new ways to shape the identities of school students and teachers. School papers were strongly implicated in the discursive construction of both a global/imperial and local/Australian identities and represent an informative case of the ways in which teaching and learning practices have been highly mobile in the field of reading.Originality/value– This research shows that the humble school reading text is an overlooked site for examining processes of the constitution of national identity and the citizen subject. It is also a reminder of the significance of communications technologies in the formation of, and struggles over, national/imperial imaginaries and that the school is an important site for studying these processes.

Two novel Talaromyces species isolated from medicinal crops in Korea

Two novel biverticillate Talaromyces species, T. angelicus and T. cnidii, were collected from the medicinal crops Angelica gigas and Cnidium officinale, respectively, in Korea. Phylogenetic analyses with the nuclear ribosomal internal transcribed spacer (ITS) region and the β-tubulin gene as well as morphological analyses revealed that the two species differ from any known Talaromyces species. Talaromyces angelicus is related to T. flavovirens in the phylogeny of the ITS region, but the new species is grouped together with Penicillium liani and T. pinophilus in terms of its β-tubulin phylogeny, and its growth rate on Czapek yeast autolysate differs from that of T. flavovirens. Talaromyces cnidii is phylogenetically similar to T. siamensis, but exhibits differences in the morphologies of the colony margin, metulae, and conidia.

Simple and efficient recycling of fungal selectable marker genes with the Cre-loxP recombination system via anastomosis

Reverse-genetics analysis has played a significant role in advancing fungal biology, but is limited by the number of available selectable marker genes (SMGs). The Cre-loxP recombination system has been adapted for use in filamentous fungi to overcome this limitation. Expression of the Cre recombinase results in excision of an integrated SMG that is flanked by loxP sites, allowing a subsequent round of transformation with the same SMG. However, current protocols for regulated expression or presentation of Cre require multiple time-consuming steps. During efforts to disrupt four different RNA-dependent RNA polymerase genes in a single strain of the chestnut blight fungus Cryphonectria parasitica, we tested whether Cre could successfully excise loxP-flanked SMGs when provided in trans via anastomosis. Stable Cre-producing donor strains were constructed by transformation of wild-type C. parasitica strain EP155 with the Cre-coding domain under the control of a constitutive promoter. Excision of multiple loxP-flanked SMGs was efficiently achieved by simply pairing the Cre-donor strain and the loxP-flanked SMGs-transformed recipient strain and recovering mycelia from the margin of the recipient colony near the anastomosis zone. This method was shown to be as efficient as and much less time consuming than excision by transformation-mediated expression of Cre. It also allows unlimited recycling of loxP-flanked SMGs and the generation of disruption mutant strains that are free of any foreign gene. The successful application of this method to Metarhizium robertsii suggests potential use for optimizing reverse-genetics analysis in a broad range of filamentous fungi.

Orientalism and identity in Latin America: fashioning self and other from the (post)colonial margin

Building on the pioneering work of Edward Said in fresh and useful ways, contributors to this volume consider both historical contacts and literary influences in the formation of Latin American constructs of the Orient and the Self from colonial times to the present. In the process, they unveil wide-ranging manifestations of Orientalism. Contributors scrutinize the other great encounter, not with Europeans but with Arabic, Chinese, and Japanese cultures, as they marked Latin American societies from Mexico, Central America, and the Caribbean to Peru, Argentina, and Brazil. The perspectives, experiences, and theories presented in these examples offer a comprehensive framework for understanding wide-ranging manifestations of Orientalism in Latin and elsewhere in the developing world.Orientalism and Identity in Latin America expands current theoretical frameworks, juxtaposing historical, biographical, and literary depictions of Middle Eastern and Asian migrations, both of people and cultural elements, as they have been received, perceived, refashioned, and integrated into Latin American discourses of identity and difference. Underlying this intercultural dialogue is the hypothesis that the discourse of Orientalism and the process of Orientalization apply equally to Near Eastern and Far Eastern subjects as well as to immigrants, regardless of provenance and indeed to any individual or group who might be construed as Other by a particular dominant culture.

Solubilization of aluminum phosphate by specific Penicillium spp.

The solubilization of hardly soluble aluminum phosphate (AlPO4) by specific Penicillium spp. isolated from wheat rhizospheric soils was investigated in Pikovskaya agar and liquid medium, respectively. Most of the Penicillium isolates except P. simplicissimum AP11 and P. variabile AP15 developed clear transparent zone around the colony margin in plate assays. Results of broth assays show that the Penicillium isolates can efficiently solubilize aluminum phosphate in Pikovskaya liquid medium, and vary in their capabilities to release soluble phosphate from aluminum phosphate. All the isolates exhibit different abilities to lower the pH and increase the titratable acidity in the broth compared to the control. HPLC analysis shows that most of the isolates except the species of P. aurantiogriseum can excrete different concentrations of organic acids, including gluconic acid, citric acid, oxalic acid, malic acid and tartaric acids, in the broth. The release of soluble phosphate by the isolate P. oxalicum AP2, which is the best solubilizer of aluminum phosphate among the isolates, is accompanied by a significant drop of pH and an obvious rise of titratable acidity during 7 d of aluminum phosphate-solubilizing experiments. The effects of temperature, initial pH, concentration of aluminum phosphate and shaking speed on aluminum phosphate solubilization by P. oxalicum AP2 were also investigated, and the maximum contents of soluble phosphate released are recorded at temperature 30 °C, initial pH 6, aluminum phosphate concentration 20 g/L, and shaking speed 160 r/min.

First Report of Brown Rot Caused by Monilinia fructicola on Apple in Italy.

Monilinia fructicola (G. Wint.) Honey, the causal agent of brown rot, is one of the most important fungal pathogens of stone fruit but may also affect pome fruits. The pathogen is common in North America, Oceania, South America, and Asia. It is a quarantined pathogen in Europe (3), but was recently detected in apple from the Czech Republic, Germany, and Serbia (1,2,4). In January 2012, during a survey for fungal postharvest pathogens, stored apple (Malus domestica Borkh.) belonging to the cultivars Gala and Pink Lady showing brown rot symptoms were observed in the Emilia Romagna region, Italy. Typical decay spots were circular and brown, tending toward black. Decayed tissues remained firm, and numerous grayish pustules containing spores appeared on rotted areas. The pathogen was isolated on V8 juice agar and culture plates were incubated at 25°C in darkness for 5 days. A conidial suspension was spread on malt extract agar and single spores were selected. The colonies were morphologically identified as M. fructigena. Two colonies developing a gray mass of spores in concentric rings with the reverse side black were further studied by molecular tools. The colony margins were even and the conidia were one-celled, limoniform, hyaline, and 12.1 to 17.4 × 8.4 to 11.2 μm. The ribosomal ITS1-5.8S-ITS2 region was PCR-amplified from genomic DNA obtained from mycelium using primers ITS1 and ITS4. A BLAST search in GenBank revealed the highest similarity (99%) to M. fructicola sequences (GenBank Accession Nos. HQ893748.1 and FJ515894.1). Pathogenicity was confirmed using surface-sterilized mature 'Gala' apples, wounded with a sterile needle, and inoculated with an isolate conidial suspension (103 spores/ml). A 20 μl droplet was placed in the wound; control fruits received sterile water without conidia. After 5 days of incubation at 20°C in plastic containers with high humidity, typical symptoms of brown rot developed on inoculated fruits, while control fruits remained symptomless. The fungus isolated from inoculated fruit exhibited the same morphological and molecular features shown by the original isolates. To our knowledge, this is the first report of the fungus M. fructicola on apple in Italy. Further studies are necessary to determine geographic distribution, prevalence and economic importance of this quarantine organism in Italy.

Rapidly Developing Yeast Microcolonies Differentiate in a Similar Way to Aging Giant Colonies

During their development and aging on solid substrates, yeast giant colonies produce ammonia, which acts as a quorum sensing molecule. Ammonia production is connected with alkalization of the surrounding medium and with extensive reprogramming of cell metabolism. In addition, ammonia signaling is important for both horizontal (colony centre versus colony margin) and vertical (upper versus lower cell layers) colony differentiations. The centre of an aging differentiated giant colony is thus composed of two major cell subpopulations, the subpopulation of long-living, metabolically active and stress-resistant cells that form the upper layers of the colony and the subpopulation of stress-sensitive starving cells in the colony interior. Here, we show that microcolonies originating from one cell pass through similar developmental phases as giant colonies. Microcolony differentiation is linked to ammonia signaling, and cells similar to the upper and lower cells of aged giant colonies are formed even in relatively young microcolonies. A comparison of the properties of these cells revealed a number of features that are similar in microcolonies and giant colonies as well as a few that are only typical of chronologically aged giant colonies. These findings show that colony age per se is not crucial for colony differentiation.