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1.
A Conidiobolus isolate growing optimally at 40°C was isolated from decomposing leaf litter and has been designated as a new species, Conidiobolus thermophilus. Colony growth, conidial discharge and smooth zygospore formation was rapid at 40°C, while comparative growth at 35 and 45°C was slower. On the basis of its thermophilic character and morphological distinctness from all other species, the isolate is considered as a species new to science. There have been no published reports of any thermophilic or thermotolerant strains of Conidiobolus. The present fungus was isolated as part of an ongoing programme of selective isolation of unusual/rare thermophilic fungi from compost and decomposed terrestrial plant materials.  相似文献   

2.
DNA was prepared from cyanobacteria freshly isolated from coralloid roots of natural populations of five cycad species: Ceratozamia mexicana mexicana (Mexico), C. mexicana robusta (Mexico), Dioon spinulosum (Mexico), Zamia furfuraceae (Mexico) and Z. skinneri (Costa Rica). Using the Southern blot technique and cloned Anabaena PCC 7120 nifK and glnA genes as probes, restriction fragment length polymorphisms of these cyanobacterial symbionts were compared. The five cyanobacterial preparations showed differences in the sizes of their DNA fragments hybridizing with both probes, indicating that different cyanobacterial species and/or strains were in the symbiotic associations. On the other hand, a similar comparison of cyanobacteria freshly collected from a single Encephalartos altensteinii coralloid root and from three independently subcultured isolates from the same coralloid root revealed that these were likely to be one and the same organism. Moreover, the complexity of restriction patterns shows that a mixture of Nostoc strains can associate with a single cycad species although a single cyanobacterial strain can predominate in the root of a single cycad plant. Thus, a wide range of Nostoc strains appear to associate with the coralloid roots of cycads.Non-standard abbreviations bp base pairs - kbp kilobase pairs - RFLP's restriction fragment length polymorphisms  相似文献   

3.
Two new species of Conidiobolus were isolated from Anhui Province, China. A polyphasic taxonomic approach comprising morphological characteristics and molecular data (the nuclear large subunit of ribosomal DNA and the translation elongation factor 1 alpha gene sequences) was applied to determine their novel taxonomic status in the genus Conidiobolus. The new species C. mirabilis is a sister group to C. thromoides, but morphologically differs by smaller primary conidia and a unique formation of zygospores among two to four adjacent hyphal segments. The other new species C. pachyzygosporus characterized with thick-walled zygospores is phylogenetically closely related to C. antarcticus, C. couchii, and C. osmodes.  相似文献   

4.
The new corticolous species Arthonia isidiata is described from the Pacific lowlands of Costa Rica. A. isidiata is characterized by minute, cylindrical to coralloid isidia produced on the thallus surface. The species currently is known only from the type locality in Corcovado National Park, where it occurs abundantly in the coastal rainforest around Sirena Biological Station.  相似文献   

5.
Two new species ofConiochaeta, isolated from Japanese soils, are described and illustrated:C. cephalothecoides, which is characterized by dark brown ascomata clothed with short setae, cylindrical asci and ovoid to almond-shaped or pyriform ascospores with a longitudinal germ slit; andC. dumosa, which is characterized by dark brown ascomata clothed with short setae and dense hyphal hairs, cylindrical asci and ellipsoid-fusoid ascospores with a longitudinal germ slit. These species are distinguished from most species of the genus by the unique cephalothecoid peridium of their ascomata. The associated anamorphs of both species are assignable to the form-genusLecythophora.  相似文献   

6.
The phycobiont of all species ofLempholemma analyzed is attacked by haustoria. The haustoria of these five species ofLempholemma and of two species with unknown apothecium but with a thallus quite similar toLempholemma are described. They show distinct morphological and functional characters which allow species delimitation.
Frau Prof. Dr.Elisabeth Tschermak-Woess zu ihrem 70. Geburtstag gewidmet.  相似文献   

7.
Biodegradation of chlorinated pesticide γ-hexachlorocyclohexane (lindane) by a nonwhite rot fungus Conidiobolus 03-1-56 is reported for the first time. Conidiobolus 03-1-56, a phycomyceteous fungus isolated from litter, completely degraded lindane on the 5th day of incubation in the culture medium, and GC-ECD studies confirmed that lindane removal did not occur via adsorption on the fungal biomass. Degradation studies using different medium compositions showed that nitrogen/carbon limiting conditions (stress conditions) and presence of veratryl alcohol, induced the secretion of extracellular oxidative enzymes, which enhanced the rate of lindance biodegradation. Under optimum nutrient-limiting conditions, GC-ECD and GC-MS analysis showed complete absence of any degradation metabolite, indicating that lindane was completely mineralized. Assays for tannic acid utilization and lignin peroxidase showed similar enzymatic profiles between Conidiobolus 03-1-56 and standard white rot fungi Pleurotus ostreatus 1200 and Trametes versicolor 1086. Although Conidiobolus 03-1-56 showed a reduced enzyme activity compared to white rot fungi, preliminary evidence indicates that enzymes responsible for lignin degradation by white rots play a key role in lindane degradation by Conidiobolus 03-1-56.  相似文献   

8.
The morphology and ultrastructure of associative microsymbiont complexes (AMC) isolated from the ferns Azolla pinnata and Azolla sp. and the apogeotropic roots of the cycad Cycas revoluta were studied. The composition of the AMC obtained includes the cyanobionts (symbiotic cyanobacteria) and satellite bacteria (SB). It was found that two types of cyanobacteria that substantially differ in their morphological organization are likely present as cyanobionts in the coralloids of C. revoluta. The isolated cyanobiont strains exhibited the morphological traits and regularities of development typical of the genus Nostoc; they were characterized by the ability of their cells to divide in mutually perpendicular planes. When isolating AMC from different morphological zones of C. revoluta apogeotropic roots, SB growth was revealed only around the pieces corresponding to the coralloid apical zone. No AMC components were revealed around the segments of the basal growth zone. Pure cyanobiont cultures were obtained from the AMC of C. revoluta coralloids. The AMC isolated from the ferns A. pinnata and Azolla sp. are characterized by obligate mutual dependence of the partners (the cyanobiont and SB).  相似文献   

9.
Summary Several species of the Plasmodiophoraceae, Olpidiopsidaceae and Lagenidiaceae were isolated on various substrata from the soils of Oceania. Among these were two parasites of rotifer eggs,Lagenidium septatum andMyzocytium fijiensis. The former species is characterized primarily by septation of the thallus into segments which develop into resting spores without sexual fusions.Mycozytium fijiensis resembles somewhatM. zophthorium but differs from it by smaller zoospores which are delimited outside of the sporangium.  相似文献   

10.
Caloplaca erodens is a new species of sect. Pyrenodesmia, characterised by an orbicular, sorediate, bluish-grey thallus which is endolithic but emerges at the periphery with a white, K−, obscurely lobate prothallus. The species is frequent on calcareous outcrops and walls of isolated churches and ruins of the Central Apennines (Sibillini, Gran Sasso), where it may occur in large monospecific populations, from 1000 to 2500 m asl., and is also known from dry sites of the southern Alps. It has been found with apothecia only in the type locality, being predominantly sterile. The reproduction of this lichen is evidently linked to the release of fragments of clusters of photobiont cells and mycobiont hyphae which are continuously exposed with the dissolution of the substratum. Readily distinguished from the apparently similar endolithic C. alociza (which is characterised by numerous apothecia, black, K+ purple prothallus, and esorediate thallus), C. erodens probably belongs to the C. circumalbata complex, whose taxa are always epilithic but have a white, K− prothallus. The phylogenetic position of the new species within sect. Pyrenodesmia as inferred by ITS sequences of the nuclear ribosomal DNA is shortly discussed.  相似文献   

11.
Morphogenesis of podetia inCladonia subcervicornisis a non-linear, repeating process based upon a pattern of meristem enlargement and division. Variability in mature podetia ofC. subcervicornis, which may appear branched or scyphoid, is the result of variation early in ontogeny. The growth pattern ofC. subcervicornisrepresents a continuum of developmental stages. It is impossible to predict the form of the mature thallus ofC. subcervicornisbecause growth in this species is fluid. The morphology of the mature thallus ofC. subcervicornisis difficult to circumscribe using conventionalCladoniaterminology, because the processes that form the thallus are dynamic and heterogeneous. The meristem shapes that are produced during early ontogeny inC. subcervicornisare relatively simple, and the processes by which they are formed are uncomplicated. Yet podetial form inC. subcervicornisis difficult to interpret.  相似文献   

12.
报道了中国文字衣科地衣一新记录属——裂衣属(Chapsa A.Massal.)及其2新记录种,即印度裂衣(C.indica A.Massal.)和斑果裂衣[C.leprocarpa(Nyl.)A.Frisch],标本来自海南和广西。该属主要特征是:地衣体壳状、树皮生;具子囊盘类或色盘衣类的子囊果,固有果壳融合或不明显,具侧生侧丝;具横隔或砖壁型胞室的子囊孢子。  相似文献   

13.
The algal partner of the lichenPseudocyphellaria carpoloma is a newChlorella species,Chl. sphaerica. It has a saucer- or band-shaped parietal to subparietal chloroplast with a spherical pyrenoid surrounded by a shell of starch. In some of the fully grown cells two dictyosomes lying parallel to each other and changing their position can be observed in the living state. Reproduction occurs by up to 16 autospores. 8 otherPseudocyphellaria species are also lichenized withChlorella phycobionts, apparently belonging toChl. sphaerica. The phycobiont ofWoessia fusarioides belongs toChlorella saccharophila var.ellipsoidea, and to a strain which is morphologically almost identical to one formerly isolated from the lichenTrapelia coarctata. Its ability to gather granules of india ink on the surface of young cells is one of the remarkable characters differentiating it from the latter. In the lichen thallus its cells are regularly penetrated by fungal haustoria.  相似文献   

14.
Two black yeast isolates from plants from the Canary Islands (Spain) are described and illustrated. Absence of Woronin bodies at simple septal pores, local coralloid terminal hyphal cells, indeterminate thallus maturation, the presence of budding cells and local conversion to meristematic growth all indicate a relationship to the Dothideaceae (Dothideales, Ascomycota). Morphological properties were consistent with the genus Hormonema Lagerberg & Melin, as defined by presence of percurrent conidiogenous loci alongside undifferentiated hyphae, and results of PCR-ribotyping supported this classification. The isolates were judged to belong to a hitherto undescribed species, characterized in particular by curved conidia soon developing transverse septa. The physiological profile of this species is also described.  相似文献   

15.
Summary Seedlings ofCasuarina spp. andAllocasuarina spp. were grown from seed in the greenhouse and inoculated with a nodule suspension fromC. equisetifolia. Plants ofCasuarina spp. nodulated regularly and were effective in nitrogen-fixation. Only one species ofAllocasuariona, A. lehmanniana formed root nodules. Using these plants as source of inoculum, the isolation of a newFrankia sp. HFPA11I1 (HFP022 801) was made and the strain was grown in pure culture.Frankia sp. HFPA11I1 grows well in a defined medium and shows typical morphological characteristics. In media lacking combined nitrogen, the filamentours bacterium forms terminal vesicles in abundance and differentiaties large intrahyphal or terminal sporangia containing numerous spores. This strain, used as inoculum, nodulates effectively seedlings ofC. equisietifolia andC. cunninghamiana, forming nodules with verically-growing nodule roots. Although effective in acetylene reduction, the endophyte within the nodules is filamentous and lacks veiscles. When used to inoculated seedlings ofA llocasuarina lehmanniana, Frankia sp. HFPA11I1 induces root nodules which are coralloid and lacking nodule roots. The nodules are effective in acetylene reduction and the filamentous hyphae ofFrankia within the nodule lobes lack vesicles. Effective nodulation inA. Lehmanniana depends upon environmental conditions of the seedlings and proceeds much more slowly than in Casuariana.  相似文献   

16.
The development and asexual cycle of Gongrosira debaryana have been studied in unialgal culture. Zoospores may settle singly and develop a Pleurotham-mon-like thallus, or they may clump and so produce a thallus characteristic of Gongrosira. It is suggested that Borzi's Pleurothamnion papuasicum be considered a synonym of Gongrosira debaryana.  相似文献   

17.
Laurencia marilzae Gil‐Rodríguez, Sentíes et M.T. Fujii sp. nov. is described based on specimens that have been collected from the Canary Islands. This new species is characterized by distinctive yellow–orange as its natural habitat color, a terete thallus, four pericentral cells per vegetative axial segment, presence of secondary pit‐connections between adjacent cortical cells, markedly projecting cortical cells, and also by the presence of corps en cerise (one per cell) present in all cells of the thallus (cortical, medullary, including pericentral and axial cells, and trichoblasts). It also has a procarp‐bearing segment with five pericentral cells and tetrasporangia that are produced from the third and fourth pericentral cells, which are arranged in a parallel manner in relation to fertile branchlets. The phylogenetic position of this taxon was inferred based on chloroplast‐encoded rbcL gene sequence analyses. Within the Laurencia assemblage, L. marilzae formed a distinctive lineage sister to all other Laurencia species analyzed. Previously, a large number of unique diterpenes dactylomelane derivatives were isolated and identified from this taxon. L. marilzae is morphologically, genetically, and chemically distinct from all other related species of the Laurencia complex described.  相似文献   

18.
Starch gel electrophoresis of 17 proteins has provided data on inter- and intrapopulation genetic variation in 20 species ofPorphyra occurring in British Columbia and adjacent areas.P. cuneiformis andP. nereocystis showed no within species variation, even over ranges of more than 1000 km. Populations ofP. abbottae, P. fallax, P. fucicola, P. gardneri andP. schizophylla were characterized by fixation for certain alleles. The number of polymorphic loci in a population ranged from zero to nine, depending on the species. Six species had populations that were polymorphic at just a single locus. Only two species (P. mumfordii andP. pseudolanceolata) had populations that were polymorphic at more than three loci. These levels of genetic variation are lower than those reported for populations of JapanesePorphyra species. Eleven taxa were polymorphic for 6-phosphogluconate dehydrogenase, the most variable enzyme. No within species polymorphisms were detected for bromoperoxidase, lactate dehydrogenase, superoxide dismutase or phycoerythrin. Possible evidence for the chimeric nature of the thallus was observed only inP. mumfordii.  相似文献   

19.
Arthopyrenia endobrya from Southern Brazil is illustrated and described as a new species of lichens. The thallus is composed of filamentous green algae loosely surrounded by fungal hyphae. Both symbionts grow endophytically within the leaf cells of two species ofLejeuneaceae (Hepaticae). The algae and hyphae penetrate the cell walls of the host by means of fine perforations. The ascocarps develop between the leaves and perforate them with their apical region. The classification as a member of the genusArthopyrenia is preliminary.
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20.
The frutescent species of the lichen genusCaloplaca are usually united in sect.Thamnoma, but they do not form a natural group. They are derived from different species groups within sect.Gasparrinia from different parts of the world, presumable from species having scleroplectenchymes in cortex and medulla. The algal cells are concentrated between the scleroplectenchymatic strands in large and dense groups, from where medullary plectenchyme extends to the cortex and forms characteristic pseudocyphellae there.—Most of the species seem to be ornithocoprophilous; they grow on rocks along marine coasts where much fog is induced by cold currents.—Caloplaca cribrosa is endemic in Tasmania and New Zealand,C. regalis and the doubtfulC. ambitiosa belong to the antarctic element.C. fragillima from central Chile seems to be propagated by thallus fragments.C. coralloides andC. thamnodes are endemic to California and Baja California respectively.C. cladodes from the Rocky Mountains deviates in many characteristics from the other species i.a. by it different ontogenetic development, reduced spore septum, and cementing amyloid polysaccharides within the scleroplectenchymatic strands. The African species are characterized by their distinctly dorsiventral lobes and usually possess oil cells in some of the paraphyses.Caloplaca bonae-spei, C. fragillima andC. thamnodes are new to science.
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