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1.
J. P. van der Walt 《Mycopathologia》1970,40(3-4):231-243
Further and more conclusive investigations on the life-cycle ofCandida albicans by means of DNA analyses and micromanipulation are reported.Six main stages are recognizable in the life-cycle of the species under consideration. The sexually active haplophase consists of small cells which either convert to the diplophase by somatogamous autogamy or mutate to the sexually quiescent haplophase with circa 8 × 10–15 g DNA/cell. The nascent diplophase may develop further by budding, convert into chlamydospores or give rise to asexual endospores by internal budding. After a period of dormancy, the budding, uninucleate diplophase with circa 19 × 10–15 g DNA/cell converts when transferred toFowell's acetate agar either into uninucleate chlamydospores or, after becoming multinucleate, into gonotoconts on which the haplophase is delimited externally as buds or as conidia delimited on short sterigmata. By the cultivation of single isolated conidia it was possible to confirm that they were haploid and that heterothallism was absent. The characteristic chalmydospores formed by cultures on corn meal agar were observed to germinate on non-nutritive, 2% washed agar media. Germination occurred by bud formation which gave rise to the haplophase without the formation of a septate promycelium. Since these chlamydospores appear to function as gonotoconts, they are considered to be homologous with the teliospores of theUstilaginales.This species, together with two others also described, are consequently assigned to the redefined genusSyringospora
Quinquad which is provisionally assigned to the tulasnelloid fungi. 相似文献
2.
Summary Growth response ofRhizoctonia solani
Kühn, the damping-off fungus, to metabolites of selected antagonistic rhizospheric bacteria and fungi of some Egyptian cotton varieties, namely, two strains ofBacillus subtilis
Cohn,Aspergillus terreus
Thom, andAspergillus flavus
Link produced in culture media containing nitrate- or ammonium-nitrogen sources, proved the potency ofB. subtilis metabolites in inhibitingR. solani mycelial growth whether from nitrate- or ammonium-nitrogen culture media. Metabolite filtrates ofB. subtilis (II) are more potent than those ofB. subtilis (I). Increasing concentration of bacterial metabolite filtrates resulted in a decreased mycelial dry weight ofR. solani. The bacterial inhibitory factor forR. solani mycelial growth is partially affected by heat. Metabolite filtrates ofA. terreus from nitrate-nitrogen are slightly more potent than from ammonium-nitrogen culture media while an opposite relation is evident withA. flavus metabolites. Growth responses ofR. solani to different experimental dilutions of metabolite filtrates ofA. terreus andA. flavus proved the intervention of the nutritive factor in witholding growth of the damping-off fungus. 相似文献
3.
David J. Holloway 《Pal?ontologische Zeitschrift》2005,79(2):227-239
Eocryphops andPlagiolaria are revised and a new species,E. albertii, is described from the Eifelian of Morocco.“Trimerocephalus” cyclophthalmus
Walther, 1907, a species long assigned toEocryphops, is regarded as a junior subjective synonym of the type species ofPlagiolaria, Pl, plagiophthalma. Eocryphops originated in the evolutionary lineage leading toPhacops (s.str.), whereasPlagiolaria was probably derived fromLochkovella. Although they have been linked with the Late Devonian group of small-eyed and blind phacopids includingCryphops and its relatives. neitherEocryphops norPlagiolaria is ancestral to these forms. Confirmed occurrences ofEocryphops andPlagiolaria are from regions that were situated on the North Gondwana margin or on plates associated with this margin. 相似文献
4.
It has been shown by experimentation that two morphologicallydistinct clones of Fragilaria crotonensis Kitton, isolated fromthe plankton of Windermere at approximately the same time, wereaffected quite differently by the chytrid Rhizophydium fragilariaeCanter. In one case the diatom filaments became heavily parasitizedand could be used for the maintenance of the fungus. In theother case infection was negligible. Additional clones, representative of these two morphologicalforms, from other bodies of water in the Windermere drainagebasin were tested. The same pattern of infection or relativenon-infection again ensued in direct accordance with the particulartype of filament used. Some preliminary experiments undertaken with a second, as yetlittle known chytrid parasite of F. crotonensis are reported.In this instance the fungus appeared to find its natural hoston cells belonging to the morphological form which failed tosupport the continued increase of R. fragilariae. The parasitism of morphological variants of F. crotonensis bythese fungi in the wild from Britain and else where is discussed. Fragilaria crotonensis Kitton, Rhizophydium fragilariae Canter, chytrid, diatom, parasitism, culture 相似文献
5.
A taxonomic reevaluation of two little-knownBrimeura taxa,B. fontqueri (Pau)Speta andB. duvigneaudii (L. Llorens)Rosselló et al., has been made.Brimeura fontqueri, described from the Iberian peninsula, has been put into synonymy ofB. amethystina (L.)Salisb., since it could not be distinguished on morphological, anatomical or cytogenetic grounds.Brimeura duvigneaudii, from the Balearic Islands, is closely related toB. amethystina and has 2n=28 chromosomes. It differs from the latter by its naked bulbs lacking dark cataphylls, and its narrower leaves
and whitish corollas. Accessory chromosomes are reported for the first time in the genus. Karyological instability (with chromosome
numbers ranging from 2n=28 to 42) is reported for a population ofB. fastigiata (Viv.)Chouard. A key to the recognized taxa ofBrimeura is provided. 相似文献
6.
Osbertia, a stoloniferous group confined to the montane regions of Mexico and adjacent Guatemala, was first proposed as a genus byGreene (1895), but most workers have retained the taxon as part ofHaplopappus. It is clearly closer toNoticastrum, Erigeron orHeterotheca than it is toHaplopappus sensu stricto. The present treatment recognizes two species, a widespread highly variableOsbertia stolonifera and a newly describedO. chihuahuana from northwestern Mexico. Distribution maps, distinguishing features, full synonymy and illustrations are presented. 相似文献
7.
Summary and conclusion We have been able to establish typical characteristics of the species, in artificial culture media, of the fungus causingPosadas-Wernicke's disease. Our work is base on the study of ten strains of the fungus and on their retrocultures — obtianed by inoculation of these strains in laboratory animals — in variosu culture media, among them cornmeal agar (Emmons media) which in our opinion is a medium indispensable for the differencing and for the classification of the fungus from other agents which produce syndromes of a like nature.A revision was made of the literature of the morphology of the causal agent ofPosadas-Wernicke's disease and an analysis of the predominant and characteristic fructification of the fungus. In attention to the above facts, we think that the fungus in question should be included in the genusAleurisma
Link, 1809. Therefore, admitting the validity of this genus, we believe that the name of the etiological agent ofPosadas-Wernicke's disease should be changed toAleurisma immitis, the diagnosis being justified by the microscopic study inEmmons media and completed by the forms found in a medium rich in glycides. The diagnoses is the following:
Aleurisma immitis. — In substratis pauperibus gignuntur hyphis mycelicis hyalinis, septatis, satis ramosis, ramulis in angulo pene recto; aleuriis abundantissimis, valde simplicibus, centralibus et regulariter seriatis, vel apicalibus, rarissime lateralibus, sessilibus, rare pedicellatis, rectangularibus, hyalinis, aliquoties in racemis et thyrsis dispositis. Spirae saepe videntur. In substratis carbohydratis plenis, chlamydosporis intercalaribus et apicalibus abundantibus; aleuriis et spiris nec numerosis aut typicis quam in pauperibus substratis.(so called Coccidioidomycosis) 相似文献
8.
Franz Speta 《Plant Systematics and Evolution》1979,132(1-2):1-26
In 83 species of the familiesMonotropaceae, Apocynaceae, Oleaceae, Scrophulariaceae, Lentibulariaceae, Bignoniaceae, Martyniaceae, Myoporaceae, Verbenaceae, Lamiaceae, Campanulaceae, andLiliaceae, protein bodies in the cell nuclei have been found, in 68 of these species for the first time. On the basis of their structure in accordance with morphological characters the generaBurgsdorfia, Hesiodia, Olisia, andPhlomoides of theLamiaceae are accepted;Lamium is divided intoLamium, Lamiastrum andOrvala; two new combinations are established:Kickxia campyloceras (Rech. fil. &Esfandiari)Speta andEtornotus papilionaceus (Burm. in L.)Speta. Deviating shape or lack of protein bodies corroborate former taxonomic decisions, e.g. the transfer ofMonotropa toMonotropaceae or the separation ofGaleopsis andLadanum; Veronica schmidtiana should not be included inPseudolysimachion. Systematic affinities are discussed primarily withinScrophulariaceae because nuclear protein bodies have been studied already in many species of this family. ForCampanula patula two 2 x populations are reported.
Herrn Professor Dr. L.Geitler zum 80. Geburtstag gewidmet. 相似文献
9.
T. Raghunath 《Mycopathologia》1966,30(3-4):209-215
Summary 1. A new species ofAlternaria isolated from the diseased plants ofCarum copticum L.Peucedanum graveolens
Benth. &Hook f. andFoeniculum vulgare
Mill. is described and compared with other species affecting Umbelliferae.2. TheCoriandrum isolate described by the writer asAlternaria poonensis
Raghunath is a shy sporulator in artificial culture with long beaked muriform spores formed singly at the end of comparatively short conidiophores.3. The isolate from the other three host plantsCarum copticum L.,Peucedanum graveolens
Benth. &Hook f. andFoeniculum vulgare
Mill. is named asAlternaria umbellifericola sp. nov. and is a profusely sporulating species, forming long chains of spores with rudimentary beak.4. TheCoriandrum isolate (Alternaria poonensis) has a narrower temperature range (25–30° C) than theCarum isolate (20–35° C) for optimum sporulation.5. TheCoriandrum isolate is pathogenic toCarum but not toDaucus carota L.6. TheCarum isolate is pathogenic toDaucus carota but does not infectCoriandrum sativum L.7. TheCoriandrum isolate has a wider host range among the Umbelliferae than theCarum isolate.Part of the M.Sc. thesis submitted to the Poona University, 1964. 相似文献
10.
John M. Malinky 《Pal?ontologische Zeitschrift》2006,80(1):88-106
Topotype specimens of the Middle OrdovicianHyolithes acutus
Eichwald, 1840, which is the type of the genus that lent its name to a family, order, class, and even phylum according to some, andH. latus
Eichwald, 1860 allow that genus and those species to be firmly established on a sound, morphologic basis. In addition, preservation
of the types ofHyolithes striatus
Eichwald, 1860 is sufficiently good to warrant reassignment toDorsolinevitus
Syssoiev, 1958. In contrast, the type ofH. insularis
Eichwald, 1860 is incompletely preserved, and this species is not recognizable beyond the type material. The concept of the family
Hyolithidae is revised to more closely conform to the morphology ofHyolithes, with authorship herein ascribed toSyssoiev (1958) rather than toNicholson (1872). The stratigraphic distribution of these taxa suggests thatHyolithes as defined herein first appears in the Middle Ordovician, but extends into at least the Lower Devonian, as suggested by two
species from the Barrandian region of the Czech Republic. Their geographic distribution further re-enforces the notion of
two distinct paleobiogeographic provinces based on hyoliths, a Mediterranean province and Baltic province, with almost no
mixing of hyolith faunas during the Ordovician.
相似文献
11.
V. P. Sahni 《Mycopathologia》1966,28(1-2):23-32
Summary In this paper the author has described eight more interesting foliicolous ectoparasites from Jabalpur (M.P.) India. Out of thesePyrenochaeta mitteriellae
Sahni an hyperparasite onMitteriella zizyphina
Syd. colonising leaves ofZizyphus xylopyra
Willd.,Chaetothyrium jasminicola
Sahni onJasminum sambac
Ait., andMyiocopron parviflorae
Sahni onIxora parviflora
Vahl are reported as new species.Micropeltis ekmanii
Petr. &Cif. on leaves ofCarissa spinarum L.,Asterinella ixorae
Ryan on leaves ofIxora parviflora
Vahl andPlenotrichum sp. on leaves ofCasearia tomentosa
Roxb. are three new fungus records for this country. The remaining two fungi viz.Asterina tonduzi (Speg.)Syd. onFlacourtia ramontchi
L'Herr. andBalladynopsis negrii (Cast.) M. B.Ellis onRandia dumetorum
Lamk. are new state reocrds. 相似文献
12.
In a previous paper (Hodkinson &Hunter, 1970a) we reported that salmon, suffering from a disease called ulcerative dermal necrosis, appeared to have precipitating antibodies to the mycelium of a fungus associated with their diseased skin lesions. This was confirmed when antigens were prepared from pure cultures of the fungus, a species ofSaprolegnia (Hodkinson &Hunter, 1970b). In this paper we describe the effects of culture media on the antigenicity ofSaprolegnia mycelium, as detected by double gel diffusion with salmon sera. 相似文献
13.
Helene Schiman-Czeika 《Plant Systematics and Evolution》1988,158(2-4):283-288
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
14.
A study of both silicified and nonsilicified specimens of Permian reticularioid brachiopods from South China suggests thatPermophricodothyris, a genus previously rarely reported from China, is actually very common and abundant in the Middle and especially Upper Permian
of South China. This study also clarifies, for the first time, that many of the reticularioid brachiopod species previously
described asSquamularia in fact belong toPermophricodothyris. The new data presented in this paper also allows a critical evaluation ofPermophricodothyris in relation to its closest allies:Phricodothyris, Squamularia, Bullarina andNeophricodothyris. The revision reveals that a total of 18Permophricodothyris species are present in the Middle and Upper Permian of South China, with only one species,P. squamularioides, having survived the Permian-Triassic mass extinction. Two species,P. grandis (Chao) andP. guangxiensis
Han, Zhou & Wang, are redescribed here, providing critical new information on the morphology and taxonomy of these species. 相似文献
15.
Summary The type specimen ofGymnoascus verticillatus
Smith was studied and is described as the type of a new, monotypic genus,Actinodendron. The new genus is characterized by the formation of brown to dark colored ascocarps bearing brown appendages with verticels of short branchlets. Ascospores ofA. verticillatum (Smith)Orr &Kuehn are pale brown and almost discoid. Additional specimens of this species are reported. 相似文献
16.
Three species ofOcruranus
Liu, 1979 are described from the Bastion Formation of North-East Greenland, of late Early Cambrian (middle Dyeran of North American
usage) age, representing the youngest record of a genus originally described from the earliest Cambrian Meishucunian Stage
of China. An accompanying species, tentatively assigned toXianfengella
He &Yang, 1982, seems also to be present in South Australia in strata of late Early Cambrian (Botoman of Siberian usage) age, although
also this genus was described originally from the Meishucunian.Ocruranus andXianfengella from China have been interpreted as possibly parts of coeloscleritophoran scleritomes, perhaps halkieriids, rather than individual
molluscan shells. Their shell form is not typical of helcionelloids which otherwise dominate the Early Cambrian molluscan
record, but conclusive evidence of affinity is not forthcoming from the Greenland records. New taxa:Ocruranus septentrionalis n. sp. andOcruranus tunuensis n. sp.
相似文献
17.
G. P. Agarwal 《Mycopathologia》1962,17(4):309-314
Summary This paper describes five foliicolous fungi imperfecti from Jabalpur in India. It includesPhyllosticta hasijai
Agarwal on leaves ofAcacia melanoxylon
R. Br. andCercospora anisochilicola
Agarwal onAnisochilus eriocephalus, two new species,C. jasminicola
Mueller &Chupp onJasminum sp. andC. achyranthina
Thirum. &Chupp onAchyranthes aspera L., two new records for the state, andPestalotiopsis glandicola (Cast.)Steyaert onCassia tora L., a new addition to the fungus flora of India. 相似文献
18.
19.
Jan Kohlmeyer 《Mycopathologia》1968,34(1):1-5
Summary A new species ofTrematosphaeria
Fuck.,T. mangrovis
Kohlm. sp. nov., is described. The fungus occurred as perthophyte in roots ofRhizophora racemosa
Meyer in West Africa (Liberia) and is classified as a marine species. The taxonomical situation of the Ascomycete is discussed and some ecological considerations are given.Support in part by grant GB 5587 of the National Science Foundation is gratefully acknowledged. Mrs.Erika Kohlmeyer kindly prepared the drawings. 相似文献
20.
The paleobiology of the Cretaceous neoselachian shark,Squalicorax, has largely been based on isolated teeth. We examined partial and nearly complete skeletons of three species ofSqualicorax, S. falcatus (Aoassiz),S. kaupi (Agassiz), andS. pristodontus (Agassiz), that were collected from the U.S.A. These specimens suggest that the total body length (TL) ofS. falcatus typically measured 1.8–2.0 m, and probably did not exceed 3 m. Moderatesized individuals ofS. kaupi andS. pristodontus perhaps measured about 3 m TL. AlthoughS. pristodontus was the largest form among the three species examined, this taxon possessed a set of large jaws (with large but fewer teeth)
relative to its body size compared toS. falcatus orS. kaupi. This suggests that tooth size is not an accurate indicator of the TL if one compares oneSqualicorax species to another. Neurocranial features suggest that the vision ofSqualicorax was not as acute as that of a contemporaneous macrophagous lamniform shark,Cretoxyrhina mantelli (Agassiz) , but olfaction ofSqualicorax may have been better thanC. mantelli. The morphology of placoid scales suggests thatSqualicorax was capable of fast swimming. New skeletal data support the view that the feeding dynamics ofSqualicorax was similar to the modern tiger shark (Galeocerdo
Müller & Henle). The present data do not allow for exact ordinal placement, but, contrary to some previous interpretations,Squalicorax can be excluded from the Hexanchiformes and Orectolobiformes. The taxon should more appropriately be placed within the Lamniformes
or Carcharhiniformes.
相似文献