Slimy Masses Research Articles

Gnomoniopsis associated with necrosis of leaves and chestnut galls induced by Dryocosmus kuriphilus

Chestnut (Castanea spp.) is a very important crop in the Monti Cimini area (Viterbo, Italy) which is seriously infested with the key pest, chestnut gall wasp Dryocosmus kuriphilus (Speranza et al., 2009). In May 2009 such seriously infested chestnut plants in the Monti Cimini area were found with necrotic leaves and galls. Lesions on leaves were irregular and variable in size, lemon green to amber in colour with green margins. Initially, galls were olive green then became dark brown. Inside the galls larvae of chestnut gall wasp were dead. Tissue from the edge of lesions was surface-sterilized using 1% sodium hypochlorite, rinsed in sterile distilled water and aseptically cut in 5–10 pieces not exceeding 5 × 5 mm, plated on potato dextrose agar (PDA) in Petri dishes containing an antibiotic solution (0·2% streptomycin sulphate) and incubated at 20 ± 3°C. Light brown fungal colonies were observed after 1 week close to the tissue and numerous orange slimy masses of conidia were observed on the culture surface. The colonies were regular in outline with a clear and thinner margin. Conidia were oval to oblong, sometimes slightly obovoid, straight or curved and measured 5·5–8·0 μm × 2·0–3·0 μm (mean = 6·8 × 2·5 μm, n = 210). The fungus was identified at Centraalbureau voor Schimmelcultures (CBS, Utrecht, The Netherlands) as an undescribed species from the genus Gnomoniopsis. Identification was based on both DNA sequencing (ribosomal ITS) and morphology (GenBank Accession Nos. EU254851, EU254854, EU254855). The pathogenicity of the fungus was tested in the Tuscia University experimental farm using freshly isolated cultures. Ten chestnut galls were inoculated, after slight pinprick injury, with an aqueous suspension containing 2 × 106 spores/mL and incubated in clean cheesecloth covered with Parafilm. Control-injured galls were sprayed with sterile distilled water and incubated in the same manner. Control plants did not show any disease symptoms 60 days after inoculation. In contrast, the fungus produced characteristic blight symptoms on 90% of the inoculated galls. Similar blight symptoms were observed on chestnut twigs inoculated with 4 mm discs of 7-day-old PDA cultures. Isolations from these lesions confirmed the presence of a fungus identical to Gnomoniopsis. Although chestnut leaf blight has been reported to be caused by some species of the genus Gnomonia (Sogonov et al., 2008), this appears to be the first record of a fungus in the genus Gnomoniopsis associated with the necrosis of chestnut galls caused by Dryocosmus kuriphilus. This Gnomoniopsis sp. has not been reported in Italy on non gall-infested leaves of chestnut trees (Cristinzio, 1986). The relationship between the necrotrophic propensity of Gnomoniopsis and chestnut gall wasp infestation is under investigation. The authors would like to thank the Regione Lazio (Italy) for financial support.

The genus Stachybotrys (anamorphic fungi) in the semi-arid region of Brazil

(The genus Stachybotrys (anamorphic fungi) in the semi-arid region of Brazil). Stachybotrys is characterized by macronematous, mononematous, unbranched or branched conidiophores, with discrete terminal and phialidic conidiogenous cells, and aseptate, reniform, ellipsoidal to spherical, smooth or verrucose conidia, which are produced in a slimy mass. Eight species have been reported from Brazil, occurring in the soil, air and leaf litter. During investigation of conidial fungi on decaying leaf litter in semi-arid areas of Brazil nine species were found: S. bisbyi (Sriniv.) G.L. Barron, S. chartarum (Ehrenb.) S. Hughes, S. globosa P. C. Misra & S. K. Srivast., S. kampalensis Hansf., S. longispora Matsush., S. nephrospora Hansf., S. nilagirica Subram., Stachybotrys parvispora S. Hughes and S. verrucispora Matsush. Stachybotrys nilagirica is a new record from Brazil. Descriptions, comments, geographic distribution and illustrations are presented for above mentioned species. A key for all species recorded in semi-arid region of Brazil is presented.

First Report of Stachybotrys chartarum Causing Leaf Blight of Tillandsia tenuifolia in China.

Tillandsia tenuifolia L. is an air plant that is native to Bolivia, Brazil, and Venezuela. It was introduced to China in 2006. In September 2008, a leaf blight of T. tenuifolia 'Bronze Tip' was observed in a greenhouse in Jurong, Jiangsu. Severe infection led to death of foliage, shoot rot, and eventual mortality of whole plants. The pathogen was isolated from the diseased leaves on potato dextrose agar and subsequently further cultured on a slide culture for 7 days. Anamorphic structures were examined under a compound microscope. Diseased plant parts were covered with abundant conidia, phialides, conidiophores, and mycelia of the pathogen. Conidiophores were simple or branched, zero to two septate, hyaline, smooth at base, brown, smooth to rough at upper portion, and 47.9 ± 7.6 × 4 ± 0.4 μm (n = 30). Phialides were one-celled, obovate, hyaline to pale brown, 8.8 ± 0.9 × 5.3 ± 0.3 μm (n = 20), and in whorls. Conidia were one-celled, ellipsoid to subglobose, dark brown to black, rough to ridged, 10.4 ± 1.4 × 6.2 ± 0.9 μm (n = 30), and in slimy masses. Using morphological characters, the pathogen was identified as Stachybotrys chartarum (Ehrenb.) S. Hughes (1). The living culture was deposited in the China General Microbiological Culture Collection Center (CGMCC 3.13634). S. chartarum, a saprophyte with a worldwide distribution, grows on various substrates such as soil, paper, dry walls, and wood. (2). It was also isolated from moldy sorghum seed and soybean root lesions (3,4). Pathogenicity on T. tenuifolia was confirmed by Koch's postulates in the laboratory. Ninety-six leaves on four plants were pricked with a sterilized needle and inoculated with a suspension of 6.35 × 106 conidia ml-1. Forty-seven leaves on two plants were pricked and sprayed with sterile water as controls. All the plants were kept in a growth chamber with a 12-h photoperiod, 28 ± 1°C, and relative humidity of 70 ± 3%. Initial lesions, which were water soaked, slightly sunken, and pinhead size, appeared on the inoculated plants in 7 days and expanded to 1.5 to 2.0 mm in 21 days. Necrotic spots subsequently coalesced and caused the death of the leaves. Infected shoots were rotten and shed leaves from the basal area. The plants died within 45 days. Symptoms were similar to those observed in the greenhouse. S. chartarum was reisolated from infected leaves. Control plants remained healthy. To confirm the identity of our isolate, DNA sequence was obtained from the internal transcribed spacer (ITS) region and deposited in GenBank (GU945205). The ITS sequence was 100% identical to S. chartarum strains whose DNA sequences were deposited in GenBank. To our knowledge, this is the first report of S. chartarum causing leaf blight on T. tenuifolia. The popularity of T. tenuifolia continues to grow in China. The disease should be monitored to determine its risk and economic significance in China and other regions.

Evidence for Deposition of Cellulose Prior to Dark-starvation Treatment During Spherulation in Physarum microplasmodia

Physarum plasmodium living as a slimy mass of protoplast in the dark is fragmented into small multinucleated microplasmodia (mPL) in a liquid medium. When mPL were exposed to several unfavorable environments, they transformed into “spherules” with the cell wall structure. We established a synchronous spherule-induction system for mPL consisting of 3 steps: Step 1, subculture in the 1% medium (1% sucrose and 1% soytone peptone) for 84 h at 25°C; Step 2, preculture in the 2% medium (2% sucrose and 2% soytone peptone) for 72 h at 25°C; and Step 3, dark-starvation treatment in the spherulation medium for 96 h at 25°C. Approximately 100% spherulation was observed within 48 h in Step 3. By fluorescence microscopy, we confirmed for the first time that cellulose was the major component of the cell wall in the Physarum spherule. From the results of experiments using the synchronous spherule-induction system and those of experiments on the inhibitory effect of 2,6-dichlorobenzonitrile (DCB) on cellulose synthesis in mPL in the preculture period, we presumed that the nourished medium in the preculture period was essential for mPL prior to spherulation to attain 100% of spherule. Our in vivo labeling experiments revealed that mPL of multinucleated protoplasts produced cellulose in the preculture period by de novo synthesis. We conclude that the Physarum plasmodia always supply themselves with materials to adapt to unfavorable environmental conditions such as starvation as rapidly as they can, even when they are under excellent conditions.

First Report of Pilidium concavum on Bergenia crassifolia in France.

Bergenia crassifolia (L.) Fritsch (elephant's ears or Siberian tea) (Saxifragaceae) is a perennial rhizomatous plant with pink flowers appearing at the end of winter. Since 1990, large, brown, and necrotic spots have been observed on numerous B. crassifolia plants at the University of Sciences in Nice, France. Spots appeared each year in the spring on newly emerged leaves and enlarged up to 1 to 3 cm in diameter during the summer, sometimes affecting more than half of the leaf surface. Leaves with spots were collected from May to November and placed in a humid atmosphere. Black, sessile, discoid conidiomata developed on the spots and exuded a pink, then brown, spore mass. When a mass was transferred onto a 1% malt agar medium, mycelium grew and then numerous, relatively spherical conidiomata (0.5 to 2.5 mm in diameter) developed and exuded a pink slimy mass, which contained many conidia. The mycelium grown at 24°C in the dark was scarce and pale, pink-beige. Under the light, the fungal culture was much darker with a fluffy mycelium and numerous conidiomata. The base of the conidiomata was dark; conidiophores were hyaline and showed little segmentation. Unicellular, cylindrical, fusiform conidia were hyaline, 5.4 to 8 μm long, and 1.4 to 1.9 μm wide. The morphology and size of conidia were comparable with previous descriptions of Pilidium concavum (Desm.) Höhn. (2,3). The ITS1-5.8S-ITS2 region of two isolates was amplified by PCR with primers PN3 and PN10 according to Mendes-Pereira et al. (1) and sequenced. The 421-nt sequence (GenBank Accession No. FM211810) was 100% identical to that of the P. concavum specimen voucher BPI 1107275 (GenBank Accession No. AY487094). P. concavum was reported to be on stored or rotting leaves or fruits of many dicotyledonous plants (2). To validate Koch's postulates, pieces of mycelium cultures with conidiomata (28 days old) were placed onto the upper surface of leaves of healthy B. crassifolia plants (10 to 12 pieces per plant). The leaf epidermis was previously wounded with a needle and a drop of melted paraffin was poured onto each piece of mycelium to prevent desiccation. Agar plugs without the fungus were placed similarly on wounded leaves of two control plants. Four inoculated and two control plants were incubated in growth chambers at either 24 or 18°C (16 h of light per day, 15,000 lx, 80% humidity). At 24°C, brown spots developed from 90% of the inoculation sites, whereas spots were observed for only 18% of the sites at 18°C. Such spots did not develop on control plants. After 2 months, healthy leaves as well as those with necrotic spots were put in humid chambers. Conidiomata formed after 4 weeks and exuded the same pink mass, which contained numerous conidia and from which the fungus was reisolated. Similar symptoms were also observed in several other locations in France and in botanical gardens in Akureyri (Iceland) and Métis (Canada), from which P. concavum was reisolated. To our knowledge, this is the first report of P. concavum on B. crassifolia.

Mycosphaerella dearnessii and Mycosphaerella pini

<i>Mycosphaerella dearnessii</i> and <i>Mycosphaerella pini</i>

Drinking Water Production from Well Water with High Sulfur and Sulfur Bacteria Content

Problems with treatment of Ahaste well water (Audru Parish, Parnu County, Estonia) were studied in field conditions. The groundwater contains a significant amount of sulfur, from which at pH=7.5–8.0 about 70–90% is in the form of hydrogen sulfide ion and 30–10% in the form of dissolved H2 S . After aeration in the summer, this water formed an unknown slimy microbial mass with a distinct sulfuric odor, which clogged the aeration tanks, catalytic filters, and even the distribution network up to the consumers. After laboratory analyses, it was established that this unknown microbial mass is obviously the filiform sulfur bacteria Thiothrix, together with particles of free sulfur. It was found that this mass formed during enrichment under warm conditions using air as the oxidizer. Under these conditions, elemental sulfur was liberated and created favorable conditions for the Thiothrix to thrive using the elemental sulfur as their food source. A new treatment technology for this well water was developed using o...

Ascoma development and phylogeny of an apothecioid dothideomycete, Catinella olivacea

Catinella olivacea is a discomycetous fungus often found fruiting within cavities in rotting logs. Because this habitat would lack the air currents upon which discomycete species normally rely for the dispersal of their forcibly ejected ascospores, we suspected an alternative disseminative strategy might be employed by this species. An examination of the development of the discomycetous ascomata in pure culture, on wood blocks, and on agar showed that the epithecium was gelatinous at maturity and entrapped released ascospores in a slimy mass. We interpreted this as an adaptation for ascospore disperal by arthropods. Developmental data also showed that C. olivacea was unusual among other discomycetes in the Helotiales (Leotiomycetes). For example, the ascoma developed from a stromatic mass of meristematically dividing cells and involved the formation of a uniloculate cavity within a structure better considered an ascostroma than an incipient apothecium. Furthermore, the ascus had a prominent ocular chamber and released its ascospores through a broad, bivalvate slit. These features, along with phylogenetic analyses of large subunit and small subunit rDNA, indicated that this unusual apothecial fungus is, surprisingly, more closely affiliated with the Dothideomycetes than the Leotiomycetes.

Saprophytic Colonization of Citrus Twigs by Diaporthe citri and Factors Affecting Pycnidial Production and Conidial Survival.

Melanose, caused by Diaporthe citri, produces reddish brown lesions on the fruit, leaves, and twigs of citrus trees, and greatly reduces the marketability of fresh fruit. Most of the inoculum is produced in pycnidia on dead twigs in the tree canopy, which exude large numbers of conidia in slimy masses. In this study, detached twigs inoculated with conidia were readily colonized and produced large numbers of pycnidia within 30 to 40 days when they were soaked 3 to 4 h on alternate days. Conidial production was measured by wetting twigs in a rain tower periodically and collecting the conidia in the runoff water. Production began after 80 days and continued for nearly 300 days. In other experiments, production of mature pycnidia on detached twigs was greatest at 94 to 100% relative humidity (RH) and at 28°C. Low RH and temperature, however, favored survival of conidia in exuded masses on twigs. In the field, colonization of detached twigs by D. citri was high in rainy season, moderate in spring and early fall, and minimal in late fall and winter. Twig colonization was positively related to the number of rain days and average temperature, but not to total rainfall. In another experiment, inoculated twigs placed in the tree canopy developed pycnidia and then produced conidial masses for about 200 days. D. citri is a serious pathogen, but a weak parasite, that survives primarily by colonization and reproduction on dead twigs.

THIS ARTICLE HAS BEEN WITHDRAWN: Glomerella acutata

THIS ARTICLE HAS BEEN WITHDRAWN: <i>Glomerella acutata</i>

A new species of Pestalosphaeria, the teleomorph of Pestalotiopsis neglecta

Three specimens of a newPestalosphaeria species were obtained from a twig ofQuercus myrsinaefolia from Kumamoto Pref., and from leaves ofRhododendron hybridum andRicinus communis from Izu Peninsula, Shizuoka Pref. The collected materials were kept moist for 1 to 2 mo after collection. Monoascospore isolates from each specimen produced identical colonies with black slimy masses of conidia on them. Morphological characteristics of the conidia accorded well with those ofPestalotiopsis neglecta not only hitherto recorded but also formed on the same specimen. Hence,Pestalosphaeria gubae sp. nov. is proposed for the new species, as the teleomorph ofPestalotiopsis neglecta.

Pseudostilbella euphorbiae, a new sporodochial hyphomycete, isolated from Euphorbia resinifera

Pseudostilbella anam. gen.nov. and Pseudostilbella euphorbiae anam. sp.nov. are proposed to accommodate a fungus isolated from lesions on living stems of Euphorbia resinifera Berg. collected in Morocco. The conidioma is a sporodochium borne on a rudimentary, brownish to greyish-brown, diffuse, KOH− stroma that is an extreme development of prosenchyma. The sparingly branched conidiophores develop from underlying pseudoparenchymatous cells. Conidiogenous cells form palisades and produce filiform, straight, or sinuous conidia. The conidiogenous system is holoblastic. Orange, slimy conidial masses accumulate on the colony surface or at the apex of synnema-like aggregations according to the location of the sporodochia. Sporodochia are sessile when colonies are grown under intense light, whereas they form at the apex of white stalks under diffuse light. Cultures grown in continuous darkness produce mycelial, synnema-like aggregations but do not sporulate. Light is thus needed for sporulation. Key words: Hyphomycetes, Euphorbia, fungal taxonomy, photomorphogenesis, sporodochial fungi.

A re-evaluation of Cylindrocladiella, and a comparison with morphologically similar genera

Cylindrocladiella is confirmed as distinct from Cylindrocladium . Species of Cylindrocladium are primarily distinguished from Cylindrocladiella by septate stipes, more numerously branched conidiophores, only penicillate conidiophores and Calonectria teleomorphs. Cylindrocladiella , however, has non-septate stipes, small 1-septate conidia, penicillate and subverticillate conidiophores, chlamydospores that are arranged in chains, phialides with extending, prominent collarettes, conidia in slimy masses (as opposed to clusters), strong cultural odours and Nectria teleomorphs. Six Cylindrocladiella spp. are recognized. C. peruviana is placed in synonymy with C. camelliae , while C. elegans and C. lageniformis are described as new. Gliocladiopsis is distinguished from Cylindrocladiella by the absence of a stipe, the presence of more numerous conidiophore branches and the formation of conidia in slimy yellow masses. Gliocladiopsis is distinguished from Cylindrocarpon by having uniformly cylindrical conidia, more numerous conidiophore branches, and more numerous phialides per branch. Cylindrocarpon tenue is shown to be better accommodated in Gliocladiopsis , and the name G. tenuis proposed. The taxonomic position of Acontiopsis is uncertain, due to its vague generic description and the absence of type material.

Microcycle Conidiation and Spore-Carrying Capacity of Colletotrichum gloeosporioides on Solid Media

The effect of spore inoculum density, medium concentration, and temperature on slime-spot formation, spore yield, and mycelium production by Colletotrichum gloeosporioides on agar media were studied with a simple microplate assay. A steady-state spore yield (spore-carrying capacity) independent of inoculum density was reached only on media that supported good fungal growth and sporulation. The spore-carrying capacity was reached earlier, the denser the inoculum. On standard mycological media a high inoculum density (2.5 x 10 spores per ml) resulted in a slimy mass of conidia forming a slime spot, a phenomenon associated with greatly reduced mycelium formation and indicative of microcycle conidiation. In contrast, for a similar inoculum density, enhanced mycelial growth preceded sporulation and overrode slime-spot formation on highly concentrated media; a very low medium concentration resulted in much less mycelium, but spore production was also decreased. Exposure to suboptimal growth temperatures of 36 to 48 degrees C for up to 8 days did not induce microcycle conidiation from inocula that did not form a slime spot at 28 degrees C.

Fruit Structure in Two Neotropical Mistletoes and Its Consequences for Seed Dispersal

Many species of tropical mistletoes have fruits with either hard exocarps visited by a particular taxon of birds, like the New World euphonias and the Old World flowerpeckers, or soft exocarps visited by a greater diversity of bird species. A comparative study of two species of Neozropical mistletoes in the Republic of Panama suggests that predation might be important in selecting for these fruit characters. Fruits of Phoradendron quadrangulare with hard exocarps have minimal predispersal predation but suffer from postdispersal predation due to clumped deposition of seeds. Fruits of Oryctanthus alveolatus with soft exocarps suffer less postdispersal predation of seeds but have high predispersal fruit loss. HEMIPARASITIC MISTLETOES OCCURRING IN TROPICAL regions of the world are mostly dispersed by birds (Kuijt 1969). Often a single taxon of frugivorous birds are implicated in seed dispersal (Ali 1931; Docters van Leeuwen 1954; Davidar 1978, 1983). Observations in India and in Central America indicated that fruits dispersed only by specialist birds have hard exocarps that are discarded by the birds. The pulp and seed are swallowed, and the seeds are excreted in slimy masses by the bird (Davidar 1978, 1983). The seeds often stick onto a branch, the ideal substrate for these hemiparasitic plants. Other mistletoe species in these areas were dispersed by a wider variety of bird species (Davidar 1978, 1983). These species had fruits with soft exocarps, and the seeds were either discarded prior to ingesting the pulp or swallowed whole and excreted or regurgitated. The seeds were more often voided in smaller clumps by these birds (Davidar 1983). This study tests the hypotheses that (1) mistletoes with hard exocarps have lower fruit predation levels than mistletoes with soft exocarps, and (2) fruits with hard exocarps have higher seed dispersal success than fruits with soft

Surface-active spore slimes

Twenty-four species of fungi with slimy spore masses were examined for surface activity of the slime. The species fell into four categories: (1) slime highly surface-active and spores dispersed primarily at the air-water interface; (2) slime rapidly spreading in the bulk phase and the spores spread throughout; (3) slime weakly spreading or insoluble in water; (4) slime insoluble in water, but showing some activity in oil or lactophenol solution. The significance of this activity with respect to spore dispersal is discussed.

A POSSIBLE MECHANISM OF DISPERSAL OF SEPTORIA SPORES

Spores of Septoria linicola, the pathogen of pasmo of flax, exude from pycnidia in slimy masses not adapted for dispersal by wind. Conidia were produced directly from the mycelium in culture, and secondary conidia were produced by germinating spores. Such spores might be dispersed by wind much more readily than pycnidiospores, and might account for rapid spread of pasmo observed in fields of maturing flax.

Aerobic heterotrophic bacteria indigenous to pH 2.8 acid mine water: microscopic examination of acid streamers.

"Acid streamers" found in acid coal mine drainage consist of bacteria trapped within an extracellular fibrillar polymer network. Inorganic compounds also precipitate within the polymer network. Several bacteria which appear to be different and are presumed to be different species are associated in the slimy mass of the "acid streamers." The "streamers" contain individual microcolonies or microcosms that can be recognized by a selective polysaccharide stain, which suggests that the slime streamer is a conglomeration of polymers produced by more than one species.

Penicillium digitatum . [Descriptions of Fungi and Bacteria

Abstract A description is provided for Penicillium digitatum . Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: On decaying citrus fruit. DISEASE: Green mould of citrus fruit. Growth is rapid atter infection, the fruit surface becoming covered in a white mould which quickly becomes olive due to the production of the conidia. The fruit then softens and begins to shrink and if exposed to the air becomes a hollow mummified shell. Distinct from Penicillium italicum (see CMI Descript. 99) which is blue-green and finally reduces the fruit to a slimy mass. GEOGRAPHICAL DISTRIBUTION: Common in all citrus producing areas, but widespread as a storage rot of citrus fruit. TRANSMISSION: Common in soil of citrus producing areas and enters the fruit as a wound parasite but will not penetrate undamaged fruit. Said to occur more frequently than P. italicum on fallen fruit on light soil in Israel (31: 603). Spores also particularly abundant in air of citrus packing houses and fruit conditioning rooms (40: 400; 41: 89).

ウナギの水生菌病に関する研究-I

In order to examine the resistance of the eel to Saprolegnia parasitica, experiments were made, with the following results, on the possibility of the fungus infecting healthy uninjured fish, on the part played by injury in susceptibility to infection and on the ability of the fungus to invade the living tissues. The fish used in the experiments were elvers and yellow eels ranging from 8 to 43cm in body length. 1) Neither elvers nor yellow eels became affected with Saprolegnia when they were in a sound condition. 2) Injury greatly lowered the resistance of elvers to Saprolegnia. Primary lesions of the skin caused by slight abrasion became the loci of zoöspore infection, from which the hyphae likely penetrated into the surrounding normal tissues of the victim. 3) Yellow eels have a high resistance to the fungus. Infection of them failed to occur even when they were injured by cutting deep on various parts of the body, by scraping a sizable portion of the skin, or by excising the skin from a small area of the body surface. 4) The mycerial growth frequently developed on coagula or slimy masses which appeared ordinarily on the surface of wound and were regarded as consisting of wound exudate and cellular debris. The growth, however, never penetrated from them into the tissues of the injured area. 5) Zoöspore infection took place easily on large necrotic areas produced on the body surface, the hyphae growing vigorously there. The mycelium, however, did not invade the surrounding living tissues, so far as the vitality of the fish was maintained.