Fungi associated with the aerial parts of Malaysian mangrove plants

The leaf surface fungi associated with nine species of mangrove plants includingAvicennia alba, A. officinalis, Bruguiera parviflora, Ceriops tagal, Rhizophora apiculata, R. mucronata, Sesuvium portulacastrum, Sonneratia alba, andXylocarpus mollucensis were studied using direct observation techniques and leaf washings. Over 40 fungal taxa were isolated from the leaf washings. Of these, species ofAspergillus, Choanephora, Cladosporium, Curvularia, Fusarium, Nigrospora, Penicillium, Pestalotiopsis, Trichoderma, andZygosporium were frequently encountered in the washings of all nine mangrove plants. Fewer species of fungi includingCladosporium oxysporum, Corynespora cassiicola, Fusarium, Penicillium, Pestalotiopsis, andZygosporium were capable of growth on the washed leaves. The major phylloplane fungus on plants with higher leaf tannin content (e.g.B. parviflora, C. tagal, Rhizophora spp., andX. mollucensis) wasPestalotiopsis. Leaves with relatively lower amounts of tannin supported the proliferation ofFusarium as the major fungus. Fungi were present on the plumule and cotyledonous sheath even before the leaves opened.Pestalotiopsis persisted throughout the development and growth of the leaves. Many of the fungi encountered on senescent leaves have been reported in earlier studies to be the primary colonisers of submerged decaying leaves.     

Mycobiota of the date palm phylloplane: description and interactions

We have analysed the mycobiota of date palm (Phoenix dactylifera, L.) leaves using several techniques. Profusely sporulating fungi (Penicillium spp. and Cladosporium spp.) developed when plating leaf fragments and leaf washings. Fusarium oxysporum, was particularly abundant in leaves infested with the red scale insect Phoenicococcus marlatti Cockerell, 1899, but an undescribed Lecanicillium cf. psalliotae was also found. Dual and overlay cultures showed interactions between palm pathogens, entomopathogenic and saprotrophic fungi. The most significant was the strong inhibition of the palm pathogen Penicillium vermoesenii caused by the entomopathogen Beauveria bassiana. No symptoms developed when F. oxysporum isolated from scale insects or the entomopathogens B. bassiana or Lecanicillium dimorphum were wound-inoculated on P. dactylifera petioles.     

Mycotoxin-producing potential of fungi associated with qat (Catha edulis) leaves in yemen

Forty-four fungal species belonging to 20 genera were isolated from 30 samples of qat leaves. The most frequent genera wereAspergillus, Alternaria, Penicillium, andCladosporium followed byFusarium, Drechslera, Chœtomium, andMucor. The most prevalent species in above genera wereAspergillus niger, A. flavus, A fumigatus, Alternaria alternata, Penicillium chrysogenum, P. citrinum, Cladosporium cladosporioides, andFusarium verticillioides. From these fungi, 17 species (39%) related to 7 genera (35%) proved to be true endophytes. Eleven out of 75 isolates were mycotoxigenic.A. alternata produced alternariol and alternariol monomethyl ether whereasA. flavus produced aflatoxins B₁ and B₂. Ochratoxin A, sterigmatocystin, citrinin and T-2 toxin were produced byA. ochraceus, A. versicolor, P. citrinum andF. oxysporum, respectively. The presence of such toxigenic fungi associated with qat leaves is considered to be a threat to public health.     

红树林内生真菌研究进展

红树林作为一种特殊的植物群落具有丰富的内生真菌资源,目前已分离鉴定的红树林真菌超过200种,成为海洋真菌的第二大类群,已报道的红树林内生真菌主要类群是链格孢霉(Alternaria)、曲霉(Aspergillus)、芽枝霉(Cladosporium)、炭疽菌(Colletotrichum)、镰孢霉(Fusarium)、拟青霉(Paecilomyces)、拟盘多毛孢(Pestalotiopsis)、青霉(Penicillium)、茎点霉(Phoma)、拟茎点霉(Phomopsis)、叶点霉(Phyllosticta)和木霉(Trichoderma)等.大部分红树林内生真菌具有较宽的宿主范围,极少数只有单一的宿主,不同红树林植物的内生真菌区系及优势种群有很大差异.红树林内生真菌的定殖因宿主植物不同部位、植株的年龄及季节和环境的变化明显不同.红树林内生真菌能产生多种代谢产物,具有抗菌、抗肿瘤等药用价值.红树林植物内生真菌的研究和开发具有重要意义.本文综述了红树林内生真菌的生物多样性及其分布、生物学功能和次生代谢产物等方面的研究进展.     

Seasonal and leaf age-dependent changes in occurrence of phyllosphere fungi of giant dogwood

To examine the relative importance of leaf age and season on the occurrence of phyllosphere fungi, temporal patterns of epiphytic and endophytic phyllosphere fungi of giant dogwood (Swida controversa) were studied with reference to leaf emergence at first occurrence and in the middle of the growing season. A total of 15 and 44 species were isolated from the surface and interior of leaves, respectively. On the leaf surface, detection rate of fungi was consistently 100% and their frequencies increased during the growing season, whereas in the leaf interior, detection rate of fungi and their frequencies were low at leaf emergence and gradually increased during the growing season. Six epiphytic and two endophytic fungi were observed frequently. A white sterile mycelium was frequent only on the surface of newly emerged leaves in the first-order shoot in May. The other 7 species increased during the growing season. The frequencies of Phomopsis sp., Pestalotiopsis sp. 1, and Trichoderma viride were higher on the leaves of first-order shoots than those of higher-order shoots that emerged between July and September, suggesting the possible effects of leaf age on their occurrence. On the other hand, the frequencies of Colletotrichum gloeosporioides, Clonostachys rosea, Cladosporium cladosporioides, and Phoma sp. 1 were not different between the first- and higher-order shoots, suggesting the negligible effect of leaf age. The influence of phenological patterns of leaf emergence of deciduous trees on the diversity and composition of assemblages of phyllosphere fungi is discussed.     

The endophytic fungi from wheat (<Emphasis Type="Italic">Triticum aestivum</Emphasis> L.)

In order to study the species composition of endophytes from wheat healthy plants in Buenos Aires Province (Argentina) and to determine their infection frequencies from leaves, stems, glumes and grains, wheat plants were collected from five cultivars at five growth stages from crop emergence to harvest. A total of 1,750 plant segments (leaves, stems, glumes and grains) were processed from the five wheat cultivars at five growth stages, and 722 isolates of endophytic fungi recovered were identified as 30 fungal genera. Alternaria alternata, Cladosporium herbarum, Epicoccum nigrum, Cryptococcus sp., Rhodotorula rubra, Penicillium sp. and Fusarium graminearum were the fungi that showed the highest colonization frequency (CF%) in all the tissues and organs analysed. The number of taxa isolated was greater in the leaves than those in the other organs analysed.     

Mycoflora of mangrove mud

Summary Thirty-nine species and four varieties of fungi are reported from mangrove mud collected from Kagh Island, Port Canning and Diamond Harbour, West Bengal, India. Of these forms twelve species and two varieties belonged to genusAspergillus and three species belonged, each toMucor, Penicillium andPreussia. Two species both ofFusarium andTrichoderma were also isolated. Two new species,Cladosporium indicum andPaecilomyces indicus and five other interesting fungi are described in detail.     

Mycological studies on the angiosperm root parasiteCynomorium coccineum L. and two of its halophytic hosts

The fungal colonization of the angiosperm root parasiteCynomorium coccineum and the halophytic hostsLimonium delicatulum andArthrocnemum glaucum were investigated in a Mediterranean salt marsh in March 1992. The main fungal inhabitants on the leaves or shoot surface of the test plants wereAspergillus niger, Penicillium chrysogenum andCladosporium herbarum. The qualitative analysis of the fungal species associating the parasite, the hosts and the non-infected plants showed similar pattern. However, the total population exhibited quantitative differences coupled with the amount and the chemical composition of the exudates on plant surface and the quantity of transpired water. The fungal catch from the aerial shoot (inflorescence) of the parasite was higher than that collected from either the leaves or aerial shoots of non-infected or host plants. The fungal density on the leaves ofL. delicatulum was higher than those isolated from the aerial shoots ofA. glaucum. Infection byC. coccineum caused a marked drop in the total fungal population on leaves or shoot surfaces of the hosts as compared to the corresponding non-infected individuals. The stimulative effect of washings on spore germination of some isolated fungal species was matched with the density of fungi on the target plants.     

Isolating high-quality RNA from mangroves without liquid nitrogen

Mangroves form unique communities in tropical coastal regions and tidal lowlands. Isolating RNA from mangrove leaves is difficult because of high amounts of secondary metabolites and polysaccharides. Conventional extraction methods produce poor-quality mangrove RNA. We present a simple, fast, and convenient protocol for isolating RNA from 5 mangrove species:Aegiceras corniculatum, Bruguiera gymnorrhiza, Ceriops tagal, Kandelia candel, andSonneratia apetala. Isolating RNA from other mangrove species is also possible. Obtained RNA was of high quality and used in an RT-PCR reaction that amplified 0.6 kb of theA. corniculatum CPI-1 gene.     

三种红树林植物健康与非健康叶片中真菌的比较

红树林叶片感染真菌后可能会向非健康状态变化,为了比较三种红树林植物海漆、秋茄和桐花树健康与非健康叶片真菌类群,明确其中真菌类群的差异,该研究从广西茅尾海红树林自然保护区采集海漆、秋茄和桐花树健康与非健康叶片,对叶片中真菌分离纯化并进行形态学鉴定,提取真菌的DNA,采用RAPD多样性、ITS序列对真菌进行分子鉴定。经过初步分析,从海漆、秋茄和桐花树中共分离到157株真菌,经过形态学和RAPD分析,可能为19种不同的真菌。采用真菌ITS序列对19种真菌代表性菌株进行分析,结果表明:19种真菌都属于子囊菌门,有15株与已有的真菌ITS序列相似性在97%以上;有4株相似性低于95%,可能为新种。海漆健康和非健康叶片分别分离到真菌7种和5种,健康叶片含了非健康叶片中所有真菌;秋茄健康和非健康叶片分离到真菌1种和9种,且健康叶片中分离到的内生真菌Dothiorella aegiceri也包含于非健康叶片分离的真菌中;桐花树健康和非健康叶片分离到真菌1种和3种,且桐花树分离的内生真菌也是Dothiorella aegiceri,其包含于非健康叶片中分离到的真菌。该研究证明,海漆内生真菌同时也可能是植物病原菌,内生真菌与植物病原菌没有明显界限;另一方面,该研究发现秋茄和桐花树叶片的病变是由外部的病原真菌感染引起,感染的原因可能是昆虫叮咬红树林植物后留下了创口,这些创口有利于真菌的感染。     

Studies on some fungi isolated from the rhizosphere of tomato plants and the consequent prospect for the control of Verticillium wilt

Summary Biological control of Verticillium wilt disease with antagonistic micro-organisms was studied. Antagonism of some fungi, isolated from tomato rhizosphere, toVerticillium albo-atrum R & B. was observedin vitro. A clearly defined zone, in which the growth of the pathogen was inhibited, was observed withPenicillium spp. (includingPenicillium chrysogenum Thom) andFusarium culmorum (S.G. Sm) Sacc., whileTrichoderma viride pers. ex Fries,Gliocladium spp. andPenicillium vermiculatum Dangeard, suppressed the growth ofV. albo-atrum by penetrating, and overgrowing it. OnlyT. viride andP. vermiculatum culture filtrate added to the Dox's agar, reduced the radial growth ofV. alboatrum. Root-dip application of culture filtrates ofT. viride andP. chrysogenum was found to be most effective in controlling the disease, followed by other species ofPenicillium andGliocladium spp. WhileFusarium culmorum provided no control. Improvement of plant height and vigour with a better yield due to culture filtrate treatment occurred. Root-dip application of antagonistic fungal propagules (T. viride, P. chrysogenum) to tomato seedlings was also very effective in controlling wilt in tomato plants grown inV. albo-atrum infested soil. Dedicated to the memory of the late Prof. Ivor Isaac with whom I had the pleasure of working     

Fungi Isolated from Flue-Cured Tobacco Inoculated in the Field with Storage Fungi

Flue-cured tobacco inoculated in the field with A. amstelodami, A. flavus, A. ochraceus, A. repens, A. ruber, and a species of Penicillium was rarely invaded by these fungi. Regardless of inoculum, the predominant fungi reisolated from green tissue were species of Alternaria and Cladosporium. After curing, A. repens, A. niger, and species of Alternaria and a species of Penicillium were the most commonly isolated fungi. The fungus used as inoculum was not the predominant fungus reisolated from green or cured tissue. Conditions during handling and storage prior to marketing probably determine when storage fungi become associated with the leaf and which species becomes predominant.     

Fungi associated with dried fish in Sri Lanka

The mycoflora of dried-salted fish from markets in Kandy, Sri Lanka was studied with emphasis on visibly spoiled dried fish. A total of 61 fungal isolates from 25 dried-fish were isolated and identified. The most prevalent fungus wasAspergillus niger. Species ofAspergillus flavus, A. fumigatus, A. glaucus, A. restrictus, Aureobasidium spp.Basipetospora halophila (a genuinely halophilic fungus)Cladosporium herbarum, Gliomastix, spp.,Penicillium chalybeum andPenicillium expansum were present. The isolated fungi did not grow in synthetic media containing more than 30% sodium chloride.Aureobasidium spp. andGliomastix spp. did not grow on dried-fish under laboratory conditions. The protective exoskeleton appeared to prevent fungal growth on dried shrimp. TheA. flavus strains isolated were not aflatoxigenic.     

Keratinophilic and other fungi isolated from combine harvester wheat and sorghum dusts and from the atmosphere of winnow sites in egypt

Three methods were used for the isolation of fungi in the present investigation: the dilution-plate method, hair-baiting technique with horse hairs and the “exposed plate” method. Sabouraud's glucose agar at 28 °C was also used as isolation medium. 102 species and 2 species varieties belonging to 36 genera were collected from combine harvester wheat and sorghum dusts and from the atmosphere of hay or winnow sites.Chrysosporium was represented by 6 species:C. asperatum, C. indicum, C. keratinophilum, C. merdarium, C. pannorum andC. tropicum. Several filamentous fungi tolerating high levels of cycloheximide and other moulds were frequently encountered in the two types of dusts and in the two atmospheres, such as members ofAcremonium, Alternaria, Aspergillus, Cladosporium, Emericella, Eupenicillium, Fusarium, Paecilomyces, Penicillium, Piedraia, Rhizopus, Scopulariopsis and others.     

Polyphenolic compounds on leaves limit iron availability and affect growth of epiphytic bacteria

Polyphenolic compounds produced by plants can chelate iron, reducing its bioavailability to plant‐associated bacteria. In response to limited iron levels, most bacteria produce siderophores to acquire needed iron quantities. The amount of phenolic compounds detected in methanolic washings of leaves of different plant species varied greatly, being nearly sevenfold higher in Viburnum tinus than in Phaseolus vulgaris. In species with high levels of total phenolics (e.g. Pelargonium hortorum), tannin concentration of leaf washings was also high and accounted for up to 85% of total phenolics. Both stimulation of production of the siderophore pyoverdine in Pseudomonas syringae strain B728a and inhibition of growth of an isogenic mutant I‐1, deficient in pyoverdine production were associated with plants harbouring high levels of leaf surface phenolics. Levels of tannic acid sufficient to inhibit growth of the pyoverdine mutant in culture in an iron‐reversible fashion were similar to tannin levels found on leaves of plants such as P. hortorum. Additionally, the amount of pyoverdines produced by P. syringae and quantified in leaf washings from a variety of plants was directly related to the concentration of tannins released from the leaf, indicating that tannins were responsible for sequestering iron. Phenolic compounds, principally tannins, may thus play an important role in plant–microbe interactions.     

Studies on the mycoflora associated with sugarcane factory waste and pollution of River Nile in upper Egypt

Sixty-nine species and four varieties that belong to 28 genera of terrestial fungi were recovered from polluted and non-polluted water and mud samples on glucose and cellulose-Czapek's agar at 28°C. The most common species from the two substrates on the two types of media were Aspergillus flavus, A. fumigatus, A.niger, Cladosporium cladosporioides, Fusarium oxysporum, Mycosphaerella tassiana and Penicillium chrysogenum. Twenty-six species belonging to 14 genera were isolated from polluted (26 species and 14 genera) and non-polluted (17species and 10 genera) mud samples on Sabouraud's dextrose agar at 28°C. The most prevalent species were Acremonium retiulum, Alternaria alternata, Aspergillus flavus, Aphanoascus fulvescens, A. terreus, Aphanoascus sp., Penicillium funiculosum and Stachybotrys chartarum.     

Interactions Between Hyphosphere-Associated Bacteria and the Fungus <Emphasis Type="Italic">Cladosporium herbarum</Emphasis> on Aquatic Leaf Litter

We investigated microbial interactions of aquatic bacteria associated with hyphae (the hyphosphere) of freshwater fungi on leaf litter. Bacteria were isolated directly from the hyphae of fungi from sedimented leaves of a small stream in the National Park “Lower Oder,” Germany. To investigate interactions, bacteria and fungi were pairwise co-cultivated on leaf-extract medium and in microcosms loaded with leaves. The performance of fungi and bacteria was monitored by measuring growth, enzyme production, and respiration of mono- and co-cultures. Growth inhibition of the fungus Cladosporium herbarum by Ralstonia pickettii was detected on leaf extract agar plates. In microcosms, the presence of Chryseobacterium sp. lowered the exocellulase, endocellulase, and cellobiase activity of the fungus. Additionally, the conversion of leaf material into microbial biomass was retarded in co-cultures. The respiration of the fungus was uninfluenced by the presence of the bacterium.     

Epidemiology of allergic disease: the fungi

Summary In indoor aerial environments and in particular that of homes, the number and type of fungal spores present in the air depend, more than on air exchange with the outside atmosphere, on the presence of sources or dispersion within the building itself. The concentration of spores is half that normally recorded outside the building, withAspergillus, Penicillium, Cladosporium, Alternaria, Mucor, Rhizopus andOidiodendron as the dominating genera. Aerosporological investigations carried out in homes should ideally be done at night, with the exposition of cultural dishes. The repetitive isolation of the same fungus may be particularly important in the etiology of allergic manifestation in man. Particular environments, if insufficiently aerated, with high levels of relative humidity and insufficient illumination, may become ecological niches particularly well suited to fungi, both during its latent form or during a phase of rapid development. Together with rapidly developing fungi, for instanceMucor andRhizopus, slow developing moulds such asPenicillium, Aspergillus andTrichoderma may also be found, characterized however by a production of a great number of easily dispersed conidia. Etiological research into the allergic manifestations of patients continuously inhaling spores responsible for particular allergies appears to be insufficiently developed.     

Fungi associated with sorghum seeds

Summary A study of the external and internal fungi associated with different varieties ofSorghum seeds has been made. The varieties tested included eighteen local varieties and twelve newSorghum varieties obtained from the Rockefeller Foundation. The external fungi were studied by preparing suspensions of superficial fungi and growing on potato dextrose agar. The internal fungi were studied by planting surface sterilized seeds on P.D.A. and pure cultures of all these fungi were prepared.The external fungi found to be associated with the different varieties included different species ofPhycomyces, Circinella, Syncephalastrum, Chaetomium, Curvularia, Cladosporium, Helminthosporium, Montospora, Pullularia, Aspergillus, Penicillium, Cephalosporium, Trichoderma, Phoma, Fusarium.The internal fungi recovered from these varieties included species ofChaetomium, Cladosporium, Curvularia, Helminthosporium, Heterosporium, Hormodendron, Pullularia, Alternaria, Aspergillus, Blastomyces, Monilia, Penicillium, Fusarium, Phoma, Phomopsis. Varieties 4403B, 1060 and 503 were found to carry a large number of fungi. Variety Black spanish was found to be entirely free from any internal or external fungus. Varieties which were free from endophytic fungi but possess external fungi only were Kaoling 301, African variety 901 and Shallus 475. Three fungi viz.,Pullularia, Heterosporium, Monilia have been recovered from theSorghum seeds for the first time.     

Airborne fungi in an Italian rice mill

Summary Studies employing volumetric spore trap (VSP) and gravity settling culture plates (GSC) were conducted in order to analyse the air spora of a rice mill at Pavia, Italy, from October-December 1988. Results revealed a variety of fungal spores belonging to different genera and including recognized rice pathogenic fungi. The most frequent genera by GSC method includedAcremonium, Alternaria, Aspergillus, Aureobasidium, Cladosporium, Epicoccum, Fusarium, Helminthosporium, Mucor, Nigrospora, Penicillium, Rhizopus, Trichoderma, Trichothecium, and some unidentified fungi. Environmental assessment of fungal spores by VSP revealed that the most prevalent fungi were:Alternaria, Cladosporium, Epicoccum, Helminthosporium, Nigrospora, Pyricularia, Tilletia and hyaline, dark and coloured types of ascospores and basidiospores. Airborne fungal spore concentrations were particularly high (5,000–6,000 spores/m³) in the rooms of the rice mill where the initial stages of rough rice transformation take place, and dropped to 2,500 spores/m³ in the last room, where workers are. During a temporary interruption of the working processes, air spora concentration dropped below 1,000 spores/m³.Cladosporium, Epicoccum andNigrospora spores were predominant in all subdivisions of the indoor environments of the rice mill.