Frequency of occurrence of fungi on wood in Malaysian mangroves

Over one hundred fungi have been reported on mangrove wood (Hyde and Jones, 1988; Jones and Kuthubutheen, 1989; Hyde and Jones, unpublished) from tropical and subtropical locations. A variety of factors affect the frequency of occurrence of these fungi, e.g . salinity, length of exposure of substrate, wood species and location within the mangrove. Two aspects are addressed in this paper: a) Comparison of the fungi present at three mangroves in Malaysia (Morib, Kuala Selangor, Port Dickson); and b) The fungi colonising specific mangrove wood, e.g. Avecennia marina, Bruguiera gymnorrhiza. Species diversity was greatest at Port Dickson with 63 fungi recorded while species composition varied from site to site. Common fungi at Morib and Kuala Selangor were Halocyphina villosa and Leptosphaeria australiensis along with Kallichroma tethys and Lulworthia grandispora at the latter site. None of these were common at Port Dickson, the dominant species at this site were Hypoxylon oceanicum and Massarina ramunculicola. A comparison of the fungi occurring on Avicennia marina and Bruguiera gymnorrhiza indicated that Halocyphina villosa was common on both timbers. Species diversity and abundance were greatest on Avicennia with the following fungi listed as common: Eutypa sp., Kallichroma tethys, Marinosphaera mangrovei, Phoma sp. and Julelia avicenniae.     

Ecology of tropical marine fungi

Lignicolous material was collected from 5 marine locations in Brunei: a rocky headland, a sandy beach, a man-made brackish lake, a healthy mangrove and an oil polluted mangrove. Higher marine fungi present were identified and their percentage occurrence noted. The common marine fungi varied from habitat to habitat. Antennospora quadricornuta was most common at the rocky headland, Corollospora pulchella at the sandy beach and Halosarpheia marina at the brackish lake. In the mangroves the most common species were Halocyphina villosa (healthy) and Cirrenalia pygmea and Lulworthia grandispora (oil polluted). Differences in species composition from one habitat to the next were observed, although some fungi occurred throughout. There were significantly less diversity and numbers of fungi in the oil polluted mangrove when compared to the healthy mangrove. Observations concerning the ecology of tropical marine fungi are made.     

Neolaugeria,a new name for Terebraria (Rubiaceae) of the West Indies

Terebraria Kuntze (1903), formerly known asLaugeria Hooker (1873) non Linnaeus (1764), has been found to be a later homonym ofTerebraria Greville (1864) and is renamed asNeolaugeria. The new combinations,Neolaugeria apiculata,N. densiflora andN. resinosa are proposed, and a key, synonymies and specimen citations (US) are provided for these species.Terebraria hotteana andT. lineolata are synonymized underN. apiculata.     

Bambusicolous fungi in Japan (3): a new combination, Kalmusia scabrispora

Leptosphaeria scabrispora collected from Phyllostachys bambusoides is reported from Japan. This species was described initially from China and has not been reported subsequently. Based on the morphological features of clypeate ascomata, long stipitate asci, and reddish-brown ascospores with median primary septum, it is transferred to the genus Kalmusia. The fungus produced a Leptodothiorella-like microconidial state in culture.     

Linocarpon angustatum sp. nov., andNeolinocarpon nypicola sp. nov. from petioles ofNypa fruticans, and a list of fungi from aerial parts of this host

Two new ascomycetes,Linocarpon angustatum sp. nov. andNeolinocarpon nypicola sp. nov., are described from petioles ofNypa fruticans in Malaysia.Linocarpon angustatum differs from species in the genus in having needle-shaped ascospores.Neolinocarpon nypicola differs from species in the genus in having filiform ascospores which gradually taper towards the ends, and ascomata developing within well developed stromata. These new species are compared with existing species and illustrated with interference light micrographs. The fungi known from aerial parts ofNypa fruticans are listed.     

Two new species of erysiphaceae from Japan

Two new powdery mildew fungi were found onCelosia argentea var.argentea (Amaranthaceae) andLonicera ramosissima (Caprifoliaceae), respectively. They were newly named and described asErysiphe celosia andMicrosphaera loniceraeramosissimae.     

Indoor airbornePenicillium species in Taiwan

Penicillium species, well-known indoor airborne fungi, are considered to be important causative agents of extrinsic bronchial asthma. For selecting the proper species for clinical investigations, it is important to know which are found indoors. In the present study, 176 plates of modified Mehrlich's Medium were exposed for 20 min in living rooms and bedrooms of 88 homes in Taipei, Taiwan. A total of 5897 colonies of fungi were isolated, varying from one to 329 per house. Of the total, 910 colonies (15.4%) were identified asPenicillium spp. The three most frequently encountered species wereP. citrinum, P. crustosum andP. implicatum. Penicillium citrinum accounted for 40.5% (369 from 28 houses);P. implicatum, for 5.2% (47 from three houses); andP. crustosum, for 2.1% (19 from seven houses).Penicillium citrinum was judged to be the most prevalent airborne fungus in Taiwan. The allergenic significance of this mold is under further investigation.     

The effects of selected physical and chemical factors on attached diatoms in the Uintah Basin of Utah,U.S.A.

The relationships of diatom species to selected physical and chemical parameters in the streams of the Uintah Basin of Utah were studied through four seasons of 1977–1978. Niche center gradient analysis, cluster analysis and correlation analysis were performed.Achnanthes minutissima, Cyclotella meneghiniana, Cymbella minuta var.latens, Fragilaria capucina, andNavicula secreta var.apiculata appear to be indicator species of high or low levels of certain water quality parameters. Several other species also showed meaningful relationships to selected physical and chemical parameters.     

Stem respiratory potential in six softwood and four hardwood tree species in the central cascades of Oregon

Mature and old growth trees of varying sapwood thickness were compared with regard to stem respiration. An increment core-based, laboratory method under controlled temperature was used to measure tissue-level respiration (termed respiratory potential) of ten different tree species. Bark (dead outer and live inner combined), sapwood, and heartwood thickness measurements were used to predict sapwood volume from stem diameter (including bark) for four of the ten species. These predictions of sapwood volume were used to scale respiratory potential to the main-bole level (excluding all branches). On the core level, species that maintained narrow sapwood (8–16% of bole radius) such as Pseudotusga menziesii, Taxus brevifolia, and Thuja plicata, had sapwood respiratory potentials in the lower bole that were 50% higher (P<0.05) than species with wide sapwood (>16% of bole radius), such as Abies amabilis, Pinus monticola, and Tsuga heterophylla. This pattern was not observed for inner bark respiratory potential, or for sapwood respiratory potential within the crown. On the main-bole level, respiratory potential per unit volume was inversely correlated to the live bole volumetric fraction (inner bark plus sapwood divided by whole bole volume) (Adj. R²=0.6). Specifically, tree species with 18–20% of the main bole alive potentially respired 1.3–3 times more per unit live bole volume than species with over 40%, suggesting that the live bole was less metabolically active in tree species that maintained large volumes of sapwood.     

Airborne fungal spores in the coastal plain of Israel: A preliminary survey

Airborne spores were monitored during the years 1993–1995 in three cities along the coastal plain of Israel: Ramat Gan, Tel Aviv (Ramat Aviv) and Haifa. Seasonal fluctuations in the concentration of airborne spores were recorded. The following genera of fungi were identified:Alternaria, Cladosporium, Coprinus, Curvularia, Drechslera. Diplococcum, Epicoccum, Fusarium, Leptosphaeria, Pithomyces, Puccinia, Sphacelotheca, Stemphylium andUstilago. Unidentified spores were very rare and in negligible numbers. The dominant airborne fungal spores wereCladosporium andAlternaria. The monthly variations in airborne spores, observed among the three cities, seem to be rather minor. The recorded levels of airborne spores were below the concentrations that are accepted as threshold levels for provocation of clinical responses.     

Two onygenalean fungi from Russian Far East soil

Two onygenalean fungi isolated from forest soil in the Sikhote-Alin reserve, Russian Far East (east Siberia), are described and illustrated:Gymnostellatospora parvula as a new species andAphanoascus canadensis as a new record.Gymnostellatospora parvula is characterized by psychrophilic growth, pale yellow to pale cinnamon ascomata with a hyphal peridium, small, hyaline discoid ascospores with an equatorial rim and more or less longitudinally ridged wall.     

Study of the nuclear cycle of four species of strictly anaerobic rumen fungi by fluorescence microscopy

The nuclear cycles of four species of strictly anaerobic rumen fungi (Neocallimastix frontalis, Piromonas communis, Neocallimastix joyonii, andSphaeromonas communis) were compared by fluorescence microscopy. The existence of two types of sporangium development and thalli was confirmed in this study. The first type involved monocentric species fitted with an endogenously developing single sporangium and with rhizoids, such asN. frontalis, P. communis, andS. communis, characterized by the presence of rhizoid-like vesicles. The second type concerned polycentric species with an exogenous sporangium development such asN. joyonii. This species is characterized by a rhizomycelium and gamma particle-like bodies within the zoospore.     

Air-borne fungi at Doha, Qatar

Thirty-five genera and 73 species, were identifiedfrom 312 daily exposures set up during theperiod March 1997–March 1998. The total fungalcatch exhibited two peaks in July and December1997 and a trough in February 1998. Cladosporium (6 spp. 40.1% of total fungi),Alternaria (4 spp., 21%) andUlocladium (4 spp., 9.2%) were the maincomponents of air-borne fungi, and thecommonest species were Cladosporium.sphaerospermum (29.7%), C.cladosporioides (6.9%), Alternaria.alternata (13.9%) and U. atrum (5%).The predominance of these dark-coloured fungiin air is discussed and is attributed to one orboth of two hypotheses. Aspergillus (9spp., 4.3%) and Penicillium (8 spp.,3.95%) came next and were represented mainlyby A.niger (1.3%) andP. chrysogenum (2.4%).Spore showers of C.cladosporioides, C. sphaerospermum, Penicillium chrysogenum and Myrotheciumverrucaria were noticed with no regularseasonal pattern.The monthly number of species ranalmost parallel to the total count of fungi.The broadest species spectrum (25–29 spp.) wasrecorded in the summer months May–August 1997and the narrowest (11–12 spp.) in February andMarch 1998.The highest monthly wind velocity wasregularly associated with higher fungal colonycounts than in case of the lowest velocity. Onthe other hand, wind direction did not exhibitany regular correlation either with the colonycounts of fungi or with the wind velocity. Highwind velocity could bring more fungal spores tobe sedimented on the surface of exposed agar.Diurnal fluctuations of fungal spores offungi displayed one peak at 12 noon when thehighest temperature and wind velocity, and theleast relative humidity were recorded and onetrough at midnight.     

Fungal Avirulence Genes: Structure and Possible Functions

Avirulence (Avr) genes exist in many fungi that share a gene-for-gene relationship with their host plant. They represent unique genetic determinants that prevent fungi from causing disease on plants that possess matching resistance (R) genes. Interaction between elicitors (primary or secondary products ofAvrgenes) and host receptors in resistant plants causes induction of various defense responses often involving a hypersensitive response.Avrgenes have been successfully isolated by reverse genetics and positional cloning. Five cultivar-specificAvrgenes (Avr4,Avr9, andEcp2 fromCladosporium fulvum; nip1fromRhynchosporium secalis;andAvr2-YAMOfromMagnaporthe grisea) and three species-specificAvrgenes (PWL1andPWL2fromM. griseaandinf1fromPhytophthora infestans) have been cloned. Isolation of additionalAvrgenes from these fungi, but also from other fungi such asUromyces vignae,Melampsora lini, Phytophthora sojae,andLeptosphaeria maculans,is in progress. Molecular analyses of nonfunctionalAvrgene alleles show that these originate from deletions or mutations in the open reading frame or the promoter sequence of anAvrgene. Although intrinsic biological functions of mostAvrgene products are still unknown, recent studies have shown that twoAvrgenes,nip1andEcp2, encode products that are important pathogenicity factors. All fungalAvrgenes cloned so far have been demonstrated or predicted to encode extracellular proteins. Current studies focus on unraveling the mechanisms of perception of avirulence factors by plant receptors. The exploitation ofAvrgenes and the matchingRgenes in engineered resistance is also discussed.     

Book Reviews

Summary

The following species are reported from Great Britain for the first time: Araudiella genistae, Cheilymenia pulcherrima, Keissleriella genistae, Sporormiella borealis, and Sporormiella grandispora. The new combination dSporormiella borealis (= Sporormia borealis Egel.) is proposed and the combination Sporormiella grandispora (Speg.) Ahmed &; Cain (= Sporormia grandispora Speg.) is validated.     

Diatoms and water quality in lowland streams in the province of northern Brabant (The Netherlands)

Summary The diatoms of two Dutch lowland streams were studied. The stream Beerze is heavily polluted by the effluent of a sewage treatment plant, causing a change in the pH from less than 4 to more than 6. The acidobiontic diatomEunotia exigua is replaced by more alkaline and eutraphentic species such asGomphonema parvulum, Cyclotelia meneghiniana andFragilaria capucina. The Simpson diversity index rises from 0.2 in the upper course to 0.9 in the middle course and maintains this level in the lower course.From stream Rosep samples of 1919–1930 and recent ones were studied. This stream is polluted now by agriculture. In the earlier samples oligo-mesotraphentic species dominated (Eunotia spp.,Melosira distans). In 1976 the species of organically polluted waters were most abundant. The oligo-mesotraphentic species were hardly recovered.In spite of the severe pollution the number of rare species in both streams is still high, compared with that in stagnant waters. Only in mesotrophic moorland pools and mesotrophic quivering bogs, which are situated in trophic gradients just like both streams, a comparable number of rare species may be found.     

Substrate type and microbial interactions as factors affecting ascocarp formation by mangrove fungi

The growth and ascocarp formation of Aigialus parvus, Lignincola laevis and Verruculina enalia in single and mixed cultures on wood of Avicennia alba, Bruguiera cylindrica and Rhizophora apiculata was studied. In pure cultures, these fungi grew well on all three species of wood. Except for Aigialus parvus on B. cylindrica, all three fungi also formed abundant ascocarps. The time needed for ascocarp formation after inoculation ranged from six to eight weeks for L. laevis on all wood species, and for V. enalia on Avicennia alba; to ten weeks for V. enalia on B. cylindrica and R. apiculata; and 12 weeks for Aigialus parvus on Avicennia alba and R. apiculata.Mixed cultures involving two or three of the test fungi delayed the onset of sporulation and affected the abundance of ascocarps formed. Sporulation by Aigialus parvus on Avicennia alba and R. apiculata was markedly reduced by L. laevis alone or in combination with V. enalia. Likewise, sporulation by L. laevis was suppressed by Aigialus parvus and/or V. enalia. In contrast, the presence of L. laevis enhanced ascocarp formation by V. enalia on all types of wood. These observations suggest the presence of interference competition among the test fungi.     

Campylobacter,salmonella and chlamydia in free-living birds of Croatia

Campylobacteriosis, salmonellosis and avian chlamydiosis are zoonotic diseases in which birds have been suggested to play an important role as reservoirs. We have investigated the prevalence of Campylobacter and Salmonella spp. and Chlamydophila sp. in 107 free-living birds belonging to 25 species from 13 families from Croatia in order to examine the natural infections caused by these agents. Campylobacter jejuni-like organisms were isolated from 2 of 107 free-living bird species examined (1.9%). Salmonella was isolated from 8 fresh fecal specimens from free-living bird species (7.4%). These isolates were identified as S. typhimurium in 4 (3.7%), and S. enteriditis in 4 (3.7%) free-living birds. These samples originated from feral pigeons (Columba livia domesticus; n=14; 28.6%), rook (Corvus frugilegus; n=13; 15.4%), buzzard (Buteo buteo; n=12; 16.7%), black-headed gull (Larus ridibundus; n=8; 12.5%) and tawny owl (Strix aluco; n=8; 12.5%). The presence of Chlamydophila sp. was not detected in the free-living birds examined during this study. Epidemiological aspects and possible significance of the examined birds as a source of infections for domestic animals and humans are discussed.