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1.
Metarrhizium anisopliae (Metchinkoff)Sorokin., can be readily cultured in quantity on a medium containing honey, peptone, and barley.Poecilocerus pictus andHeliothis obsoleta are two additional hosts of the fungus reported for the first time.  相似文献   

2.
Bremia lactucae is recorded for the first time causing downy mildew on common sowthistle (Sonchus oleraceus) and spiny sowthistle (Sonchus asper) in Brazil. The disease and etiological agent are described. Pathogencity of sporangia obtained from S. oleraceus was tested on 12 species belonging to the Asteraceae, already recorded in the literature as hosts of B. lactucae, and four commonly cultivated varieties of lettuce. All four cultivars of lettuce, S. oleraceus and S. asper showed symptoms of the disease and sporulation of the pathogen 5 days after inoculation. It has been observed that the disease occurs on Sonchus spp. throughout the year in Viçosa (state of Minas Gerais), being more common on these two hosts than on lettuce. Both weeds are very common invaders of vegetable growing areas in Brazil. This indicates that those two hosts for the fungus may be important inoculum reservoirs for disease occurring in lettuce, highlighting the need for control of these weeds as part of the procedures aimed at controlling this disease. These results are also in agreement with the views that B. lactucae is split into host‐specific infra‐specific taxa. Lettuce and sowthistles are regarded as closely related, belonging to the same subfamily and tribe in the Asteraceae (Subfamily Cichorioideae: Tribe Lactuceae).  相似文献   

3.
Summary The present paper includes ten parasitic fungi occurring at Jabalpur. These include three new species viz.Hendersonia syzygii Hasija onSyzygium cumini, Phoma ixorae Hasija onIxora sp. andPhyllosticta agarwalii Hasija onDalbergia paniculata. Colletotrichum truncatum (Schw.)Andrus &Moore onAlysicarpus bupleurifolius andPiricularia zingiberi onHedychium sp. are new fungus records for the country.Grewia hirsuta forPhyllosticta sedgwickii DaCosta &Mundkur,Lagerstroemia speciosa forPestalotiopsis versicolor (Speg.)Stey.,Zingiber officinale forCurvularia lunata (Wakker)Boedijn,Musa paradisiaca forDeightoniella torulosa (Syd.)Ellis andFlacourtia ramontchi forAlternaria tenuis Nees exPers. are new hosts record from Jabalpur, India.  相似文献   

4.
Recent studies have detected phylogenetic signals in pathogen–host networks for both soil‐borne and leaf‐infecting fungi, suggesting that pathogenic fungi may track or coevolve with their preferred hosts. However, a phylogenetically concordant relationship between multiple hosts and multiple fungi in has rarely been investigated. Using next‐generation high‐throughput DNA sequencing techniques, we analyzed fungal taxa associated with diseased leaves, rotten seeds, and infected seedlings of subtropical trees. We compared the topologies of the phylogenetic trees of the soil and foliar fungi based on the internal transcribed spacer (ITS) region with the phylogeny of host tree species based on matK, rbcL, atpB, and 5.8S genes. We identified 37 foliar and 103 soil pathogenic fungi belonging to the Ascomycota and Basidiomycota phyla and detected significantly nonrandom host–fungus combinations, which clustered on both the fungus phylogeny and the host phylogeny. The explicit evidence of congruent phylogenies between tree hosts and their potential fungal pathogens suggests either diffuse coevolution among the plant–fungal interaction networks or that the distribution of fungal species tracked spatially associated hosts with phylogenetically conserved traits and habitat preferences. Phylogenetic conservatism in plant–fungal interactions within a local community promotes host and parasite specificity, which is integral to the important role of fungi in promoting species coexistence and maintaining biodiversity of forest communities.  相似文献   

5.
Gnomonia fragariae is a poorly studied ascomycete belonging to Diaporthales. Originally G. fragariae was considered a saprophyte occurring on dead tissues of strawberry plants. Recently this fungus was found in Latvia and Sweden, and it was proven to be the cause of severe root rot and petiole blight of strawberry. Thirteen isolates of this pathogen and several other Gnomonia species occurring on rosaceous hosts were characterized by molecular analysis using nucleotide sequences of partial LSU rRNA gene and the total ITS region. The homologous regions from relevant diaporthalean taxa available in the GenBank were also included and compared with the taxa sequenced in this study. Phylogenetic analyses revealed that G. fragariae, G. rubi, and Gnomonia sp. (CBS 850.79) were genetically different from G. gnomon, the type species of the genus, and other members of Gnomoniaceae. The analyses showed that G. fragariae and Hapalocystis were genetically very closely related, forming a phylogenetic clade, which is possibly presenting a new family in the Diaporthales. Morphological comparisons of the Gnomonia species on the basis of commonly used criteria for the taxonomy of Diaporthales, so far did not reveal any evident features for the polyphyletic status of Gnomonia.  相似文献   

6.
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   

7.
Summary The present paper describes eight Foliicolous Fungi imperfecti from Jabalpur (India). These include four new species viz.Ramularia alangii Hasija onAlangium lamarckii, Colletotrichum holopteleae Hasija onHoloptelea integrifolia, Gloeosporium wendlandiae Hasija onWendlandia exserta andPhyllosticta macropycnidiai Hasija onSolanum melongena. Discosia artocreas Tode exFr. onTerminalia sp. is a new fungus record for the country raising the total number ofDiscosia from India to five.Heteropogon contortus forCurvularia lunata (Wakker)Boed. andBarleria priniotes forCercospora barlericola Payak &Thirum. are new hosts record from India, andCercospora tridacis-procumbentis Govindu &Thirum. onTridax procumbens is a new record for the state.  相似文献   

8.
ABSTRACT

Ophiocordyceps is a genus comprised by entomopathogenic fungi known to infect ten orders of insects, including Hymenoptera. Amongst the nearly 250 species described in the genus, few are known to manipulate their hosts, which are most notably ants. These species cause their hosts to die in an exposed position high above the ground while grabbing and/or biting the abaxial surface of leaves or branches, which in turn optimizes the fungus spore production and dispersal. Herein, we report on 14 social wasp species belonging to four genera (Agelaia, Mischocyttarus Polybia, and Pseudopolybia) infected by Ophiocordyceps humbertii, a common wasp pathogen. This study broadens the geographic and host range for O. humbertii and provides the first record of its ability to manipulate its host.  相似文献   

9.
This paper is concerned with the species ofGymnosporangium and their host relationships. Interest centers, not on how many hosts a fungus species may occupy, but rather with how the hosts are distributed among the species of the fungus.  相似文献   

10.
Uredinial and telial states of aMelampsora species occurring on the leaves ofSalix serissaefolia were for the first time recorded. Field observations and inoculation experiments showed that the spermogonial and aecial states of the fungus were formed onChelidonium majus var.asiaticum andCorydalis incisa. The fungus was identified asMelampsora yezoensis based on the morphological observation of all the spore states. Urediniospores were able to infectS. erocarpa andS. pierotii as well asS. serissaefolia andS. jessoensis. Salix serissaefolia, S. eriocarpa, andS. pierotii are new uredinial and telial hosts ofM. yezoensis, andC. majus var.asiaticum andC. incisa are new spermogonial and aecial hosts of the fungus. Contribution No. 124, Laboratories of Plant Pathology and Mycology, Institute of Agriculture and Forestry University of Tsukuba.  相似文献   

11.
Summary Eight monocentric fungi are reported in two provisionally identified species ofRhizosolenia from sea-water. Only two species are assigned specific names. These areRhizophydium planktonicum Canter andR. fragilariae Canter. A fungus with depressed-globose sporangia is included as a form ofR. fragilariae. Two unidentified species ofChytridium are reported. A fungus tentatively assigned toZygorhizidium and a form provisionally assigned toPetersenia are also reported and described insofar as their characteristics are known.  相似文献   

12.
Chytridiomycosis is a disease of amphibians caused by the chytrid fungus Batrachochytrium dendrobatidis. It can be highly virulent and is unusual in that it appears to drive many host species to local extinction during outbreaks. One mechanism that could facilitate this is the ability to grow saprophytically or on alternative hosts. This is common in other chytrids but has not been demonstrated for B. dendrobatidis in the field. B. dendrobatidis can grow on arthropod exoskeletons in the laboratory, and freshwater shrimp can be the most abundant animals in tropical rain forest streams. We therefore used diagnostic quantitative polymerase chain reaction to determine the infection status of freshwater shrimp from areas in which they are sympatric with frog species that have suffered declines in association with outbreaks of chytridiomycosis. We detected B. dendrobatidis on three individual shrimp belonging to two genera and collected from two widely separated streams. Two of the individuals had high levels of infection. This indicates that the presence of alternative hosts is likely to contribute to the extreme virulence of chytridiomycosis outbreaks in some systems. The presence of alternative hosts may allow B. dendrobatidis to remain in the environment after local extinctions of amphibian hosts, preventing the recovery of amphibian populations.  相似文献   

13.
B. Herting 《BioControl》1964,9(1):59-65
Summary In this revision of the European species of the genusMyxexoristops t. t. (parasites of sawflies) six species, including a new one (abietis n. sp., parasite ofCephalcia), are described by their distinguishing characters. Separate keys for the determination of males and females are given. For five species, hosts are recorded on the basis of bred material examined by the author himself.Zenillia nox hall, described from Japan is identical to the European speciesM. stolida stein (nov. syn.).   相似文献   

14.
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   

15.
Global climate change is increasing the frequency of unpredictable weather conditions; however, it remains unclear how species‐level and geographic factors, including body size and latitude, moderate impacts of unusually warm or cool temperatures on disease. Because larger and lower‐latitude hosts generally have slower acclimation times than smaller and higher‐latitude hosts, we hypothesised that their disease susceptibility increases under ‘thermal mismatches’ or differences between baseline climate and the temperature during surveying for disease. Here, we examined how thermal mismatches interact with body size, life stage, habitat, latitude, elevation, phylogeny and International Union for Conservation of Nature (IUCN) conservation status to predict infection prevalence of the chytrid fungus Batrachochytrium dendrobatidis (Bd) in a global analysis of 32 291 amphibian hosts. As hypothesised, we found that the susceptibility of larger hosts and hosts from lower latitudes to Bd was influenced by thermal mismatches. Furthermore, hosts of conservation concern were more susceptible than others following thermal mismatches, suggesting that thermal mismatches might have contributed to recent amphibian declines.  相似文献   

16.
G. Zimmermann 《BioControl》1978,23(2):181-187
Zusammenfassung Von pilzbefallenen Larven der KohlschabePlutella maculipennis Curt. wurdeEntomophthora blunckii Lakon exZimmermann isoliert. Die Art wird mit lateinischer Diagnose gültig beschrieben, die morphologischen Merkmale werden erg?nzend angegeben und erstmals durch Fotos belegt.E. blunckii w?chst gut auf koaguliertem Eidotter, weniger gut auf Sabouraud-Glucose-Agar. Mycelwachstum wurde zwischen 8° und 28°C beobachtet, dagegen nicht bei 32°C. Die Symptome infizierter Larven werden geschildert und der Pilz wird mit ?hnlichen Arten verglichen.
Summary Entomophthora blunckii Lakon exZimmermann was isolated from larvae of the diamondback-mothPlutella maculipennis Curt. and redescribed. The fungus is characterized by its elliptical to pear-shaped conidia (from infected larvae 13–20×7–11 μm, mostly 15–18×7–9 μm) with the outer membrane often inflated and its branched conidiophores forming a dense gray to faint greenish-yellowish covering over the body of the insect. The symptoms of larvae infected withE. blunckii are described. The species grows on coagulated egg yolk, less well on Sabouraud-Dextrose-Agar. Growth was observed between 8° and 28°C but not at 32°C. The fungus is compared with similar species.
  相似文献   

17.
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   

18.
On granite outcrops around Highlands, North Carolina four sympatric Danthonia grass species are infected by the fungus Atkinsonella hypoxylon (Clavicipitaceae). Danthonia epilis and D. sericea (rare hosts) are infected only in this small region, although they range more widely, while D. compressa and D. spicata (widespread hosts) are infected throughout their ranges in eastern North America. To test the hypothesis that infection of the rare hosts has recently spread from the widespread hosts, the genetic structure of fungal populations on different Danthonia hosts was investigated by isozyme electrophoresis. Two hundred isolates were collected from 46 sites and analyzed for ten polymorphic isozyme loci to examine levels of variation, genetic differentiation, and gene flow among fungal populations infecting different hosts. Genetic identities (I) indicated that isolates from within each of the widespread and rare host species pairs were homogeneous (I > 0.99), but the pairs were highly differentiated (0.66 < I < 0.69). With one exception there was no overlap in fungal genotypes isolated from the widespread hosts (12 genotypes) vs. the rare hosts (seven genotypes). Two plants of D. compressa growing sympatrically with infected D. epilis at one site were infected with a genotype characteristic of the latter species. Estimates of gene flow suggest a high degree of host-mediated reproductive isolation in A. hypoxylon, indicating that the fungus forms distinct, long-standing host races or sibling species in the southern Appalachians.  相似文献   

19.
Species with close associations to a specific host species, such as parasites and phytophages, make immense contributions to biodiversity. Hence, factors determining the variation in species richness among hosts are a main focus of ecological research. Investigations of determining factors of fungivorous species among host species are still scarce. Based on ecological patterns of parasites and phytophages, we hypothesized that the species richness of tree‐fungus beetles of the family Ciidae (Coleoptera) would increase with increasing basidiome size, niche diversity of the growth form, durability, increasing abundance and decreasing phylogenetic isolation of the host fungus. Our generalized least‐squares model, controlled by host phylogeny, revealed that Ciidae species richness increases with host abundance, but decreases with host phylogenetic isolation. In contrast with our prediction, Ciidae species richness was higher in annual basidiomes than in perennials. Pileate basidiomes revealed higher species richness than resupinate and stipitate basidiomes, which may be interpreted as being a result of their higher host niche diversity. The importance of host abundance, measured on the landscape scale, corroborates that fungivore species richness among macrofungal hosts is determined by factors similar to those that determine parasite and phytophage species richness among their hosts. © 2015 The Linnean Society of London, Biological Journal of the Linnean Society, 2015, 114 , 699–708.  相似文献   

20.
Paragordius tricuspidatus (Dufour, 1828) and Spinochordodes tellinii (Camerano, 1888) are two sympatric species of horsehair worms in southern France. Paragordius tricuspidatus was found in only one host species, Nemobius sylvestris (Bosc, 1792), while Spinochordodes tellinii was found in nine different hosts belonging to Orthoptera Caelifera. Size of nematomorphs varied strongly, but is additionally influenced by host size (in Spinochordodes tellinii) or number of parasites per host (in Paragordius tricuspidatus). Both species have a clear seasonality with Paragordius tricuspidatus occurring from June to early August and Spinochordodes tellinii occurring in August and September.  相似文献   

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