共查询到20条相似文献,搜索用时 375 毫秒
1.
An endophytic fungus, F-23, was isolated from the roots of Dendrobium officinale Kimura et Migo, an endangered Chinese medicinal plant. The sequence of the ITS region indicated that the isolate belongs
to the genus Mycena. After 4 months of inoculation, the root systems of D. officinale that were inoculated with F-23 fungus were much larger than the control’s root systems. We also observed that the hyphae
of F-23 penetrated the epidermal cells within the host’s roots and spread from cell to cell. A large number of pelotons existed
in the root cortical cells of D. officinale inoculated with F-23 fungus. Intracellular hyphae crossing through the host walls were also observed using SEM (scanning
electron microscopy). In contrast, light microscopy and SEM showed that the transverse sections of the roots of control plants
remained uncolonized. Therefore, the F-23 fungus can form mycorrhizal associations with the roots of its host plant, D. officinale, and enhance the growth of seedlings and roots. In brief, Mycena sp. was identified and shown to be a mycorrhizal fungus of the epiphytic orchid, D. officinale. This might be of potential use to the mass cultivation of D. officinale under artificial conditions. 相似文献
2.
Hajer Regaieg Aurelio Ciancio Najet Horrigue Raouani Laura Rosso 《World journal of microbiology & biotechnology》2011,27(7):1615-1623
Three isolates of Verticillium leptobactrum proceeding from egg masses of root-knot nematodes (RKN) Meloidogyne spp. and soil samples collected in Tunisia were evaluated against second-stage juveniles (J2) and eggs of M. incognita, to determine the fungus biocontrol potential. In vitro tests showed that V. leptobactrum is an efficient nematode parasite. The fungus also colonized egg masses and parasitized hatching J2. In a greenhouse assay
with tomato plants parasitized by M. incognita and M. javanica, V. leptobactrum was compared with isolates of Pochonia chlamydosporia and Monacrosporium sp., introducing the propagules into nematode-free or naturally infested soils. The V. leptobactrum isolates were active in RKN biocontrol, improving plants growth with a significant increase of tomato roots length, lower
J2 numbers in soil or egg masses, as well as higher egg mortalities. In a second assay with M. javanica, treatments with three V. leptobactrum isolates reduced egg masses on roots as well as the density of J2 and the number of galls. To evaluate the fungus capability
to colonize egg masses a nested Real-time polymerase chain reaction (PCR) assay, based on a molecular beacon probe was used
to assess its presence. The probe was designed on a V. leptobactrum ITS region, previously sequenced. This method allowed detection of V. leptobactrum from egg masses, allowing quantitative DNA and fungal biomass estimations. 相似文献
3.
Little information is known on what the magnitude of nitrogen (N) processed by ectomycorrhizal (ECM) fungal species in the
field. In a common garden experiment performed in a northern California oak woodland, we investigated transfer of nitrogen
applied as 15NH4 or 15NO3 from leaves to ectomycorrhizal roots of three oak species, Quercus agrifolia, Q. douglasii, and Q. garryana. Oak seedlings formed five common ectomycorrhizal morphotypes on root tips. Mycorrhizal tips were more enriched in 15N than fine roots. N transfer was greater to the less common morphotypes than to the more common types. 15N transfer from leaves to roots was greater when , not , was supplied. 15N transfer to roots was greater in seedlings of Q. agrifolia than in Q. douglasii and Q. garryana. Differential N transfer to ectomycorrhizal root tips suggests that ectomycorrhizal morphotypes can influence flows of N
from leaves to roots and that mycorrhizal diversity may influence the total N requirement of plants. 相似文献
4.
5.
Regeneration processes of riparian Robinia
pseudoacacia forests after clear-cutting were investigated through dendroecological and microsatellite polymorphism analyses. Age determination
of regenerated R. pseudoacacia trees based on the dendroecological analysis revealed that forests regenerating after clear-cutting were composed of trees
that mostly established within a few years after clear-cutting. This suggests that the stimulus to form new shoots was evoked
by clear-cutting but faded within a few years. Genet identification via the microsatellite polymorphism analysis showed that
ramet trees belonging to the same genet were distributed in a cluster. Almost all trees regenerated asexually through new
ramet formation on the cut stumps and residual horizontal roots after clear-cutting. AMOVA with microsatellite markers showed
that among- and within-population variations contributed 6 and 94% to the total variation, respectively, suggesting that R.
pseudoacacia trees in the forests were initially established from seeds dispersed randomly from mother trees in a wide area. 相似文献
6.
We studied the nutritional modes of the orchid Serapias strictiflora and its mycorrhizal fungus Epulorhiza sp. using the differences in carbon isotopic composition (δ13C) of C3 orchid and C4 maize tissues. We found that if cultivated in substrate lacking any organic compounds, the mycorrhizal extraradical mycelia
(δ13C = −26.3 ± 0.2 ‰) developed well, despite being fully dependent on nutrition from orchid roots (δ13C = −28.6 ± 0.1 ‰). If the mycorrhizal fungus had additional access to and colonized decaying maize roots (δ13C = −14.6 ± 0.1 ‰), its isotopic composition (δ13C = −21.6 ± 0.4 ‰) reflected a mixture of biotrophy and saprotrophy. No statistically significant differences in δ13C of new storage tubers were found between Epulorhiza-associated orchids with (δ13C = -28.2 ± 0.1 ‰) and without access to maize roots (δ13C = −28.6 ± 0.2 ‰). We conclude that autotrophy is the predominant nutritional mode of mature S. strictiflora plants and that they supply their mycorrhizal fungus with substantial amount of carbon (69 ± 3 % of the fungus demand), even
if the fungus feeds saprotrophically. 相似文献
7.
A pea rust fungus, Uromyces viciae-fabae, has been classified into two varieties, var. viciae-fabae and var. orobi, based on differences in urediniospore wall thickness and putative host specificity in Japan. In principal component analyses, morphological features of urediniospores and teliospores of 94 rust specimens from Vicia, Lathyrus, and Pisum did not show definite host-specific morphological groups. In molecular analyses, 23 Uromyces specimens from Vicia, Lathyrus, and Pisum formed a single genetic clade based on D1/D2 and ITS regions. Four isolates of U. viciae-fabae from V. cracca and V. unijuga could infect and sporulate on P. sativum. These results suggest that U. viciae-fabae populations on different host plants are not biologically differentiated into groups that can be recognized as varieties.Contribution no. 184, Laboratory of Plant Parasitic Mycology, Institute of Agriculture and Forestry, University of Tsukuba, Japan 相似文献
8.
Kurtzman CP 《Antonie van Leeuwenhoek》2011,100(3):455-462
Ogataea
parapolymorpha sp. n. (NRRL YB-1982, CBS 12304, type strain), the ascosporic state of Candida
parapolymorpha, is described. The species appears homothallic, assimilates methanol as is typical of most Ogataea species and forms hat-shaped ascospores in asci that become deliquescent. O. parapolymorpha is closely related to Ogataea
angusta and Ogataea
polymorpha. The three species can be resolved from gene sequence analyses but are unresolved from fermentation and growth reactions
that are typically used for yeast identification. On the basis of multiple isolates, O. angusta is known only from California, USA, in association with Drosophila and Aulacigaster flies, O. parapolymorpha is predominantly associated with insect frass from trees in the eastern USA but O. polymorpha has been isolated from various substrates in the USA, Brazil, Spain and Costa Rica. 相似文献
9.
Sylvie Pažoutová Petr Šrůtka Jaroslav Holuša Milada Chudíčková Miroslav Kolařík 《Mycological Progress》2010,9(4):501-507
The inconspicuous inner-bark parasite Obolarina dryophila is reported from wood of Quercus petraea and as an endophyte of Salix alba. In addition, viable ascospores of O. dryophila have been found in the gut of the oak bark weevil Gasterocercus depressirostris, suggesting a possible dissemination mechanism for the fungus. A phylogenetic analysis based on three genes (nrDNA, actin,
β-tubulin) placed Obolarina inside the genus Biscogniauxia as a close relative of the oak pathogens B. atropunctata and B. mediterranea. 相似文献
10.
Aime Didier B. Begoude Marieka Gryzenhout Michael J. Wingfield Jolanda Roux 《Antonie van Leeuwenhoek》2010,98(3):263-278
Native Terminalia spp. in West Africa provide a popular source of construction timber as well as medical, spiritual and social benefits to
rural populations. Very little is, however, known regarding the diseases that affect these trees. During an investigation
into possible diseases of Terminalia spp. in Cameroon, orange to yellow fungal fruiting structures, resembling those of fungi in the Cryphonectriaceae, were commonly
observed on the bark of native Terminalia ivorensis, and on dead branches of non-native Terminalia mantaly. In this study the fungus was identified based on morphological features as well as DNA sequence data (ITS and β-tubulin)
and its pathogenicity was tested on T. mantaly seedlings. Our results showed that isolates of this fungus represent a previously undescribed genus in the Cryphonectriaceae,
which we describe as Aurifilum
marmelostoma gen. et sp. nov. Pathogenicity tests revealed that A. marmelostoma is pathogenic on T. mantaly. These tests, and the association of A. marmelostoma with disease symptoms on T. ivorensis, suggest that the fungus is a pathogen of this important tree. 相似文献
11.
The ecology and physiology of ectomycorrhizal (EcM) symbiosis with conifer trees are well documented. In comparison, however,
very little is known about the molecular regulation of these associations. In an earlier study, we identified three EcM-regulated
Pinus expressed sequence tags (EST), two of which were identified as homologous to the Medicago truncatula nodulin MtN21. The third EST was a homologue to the receptor-like kinase Clavata1. We have characterized the expression patterns of these genes and of auxin- and mycorrhiza-regulated genes after induction
with indole-3-butyric acid in Pinus sylvestris and in a time course experiment during ectomycorrhizal initiation with the co-inoculation of 2,3,5-triiodobenzoic acid, an
auxin transport inhibitor. Our results suggest that different P. sylvestris nodulin homologues are associated with diverse processes in the root. The results also suggest a potential role of the Clv1-like gene in lateral root initiation by the ectomycorrhizal fungus. 相似文献
12.
Daniel M. Alongi Barry F. Clough Paul Dixon Frank Tirendi 《Trees - Structure and Function》2003,17(1):51-60
Mangrove partitioning and storage of macronutrients and trace metals were examined in different arid coastal settings of Western Australia. Total living biomass in three Rhizophora stylosa forests, which ranged from 233 to 289 t DW ha-1, was significantly greater than biomass in three Avicennia marina forests (range: 79-155 t DW ha-1). Although prop roots and stems were the largest single tree components for R. stylosa and A. marina, respectively, most nutrients were stored in leaves and living roots of both species. However, only a small fraction of the total nutrient pool was vested in tree biomass; the vast bulk was in soils. A large below-ground pool of dead fine roots was identified at all stands, equivalent to 36-88% DW of total living tree biomass. The amount of Ca, S, Cl, Na, Si, Fe, Mn, Zn, B, Mo and Cu vested in dead roots of both species was greater than in the total living tree biomass. The proportion of Fe and S vested in live and dead roots was exceptionally large, consistent with previous evidence of metal plaques on mangrove roots. Sulphur, iron and zinc in dead roots of both species constituted the bulk of these metals. R. stylosa trees preferentially accumulated more Mg, S, Cl, Na, Si, Fe, Mn, B and Mo than A. marina trees. Proportionally greater storage of P, N, Ca, K, Cu and Zn occurred in two of the three A. marina forests. Foliar concentrations of Mg, S, Mn, B and Mo in mangrove leaves were at the high end of the range reported for other tropical trees, but other elemental concentrations were at the low or mid-range. Nitrogen limitation in these forests is implied by a positive correlation between total tree N and net canopy production and by a lower percentage of ecosystem N in tree biomass as compared with other forests. Unlike terrestrial forests where a large proportion of nutrient capital is vested in floor litter, most elements in these mangrove forests are stored in dead roots. A large reservoir of dead roots below the forest floor may serve as a conservation mechanism, particularly in such arid oligotrophic environments. 相似文献
13.
Endophytic fungi are rich in orchids and have great impacts on their host plants. 53 endophytes (30 isolates from Dendrobium devonianum and 23 endophytic fungi from D. thyrsiflorum) were isolated, respectively, from roots and stems of Dendrobium species. All the fungi were identified by way of morphological and/or molecular biological methods. 30 endophytic fungi in
D. devonianum were categorized into 11 taxa and 23 fungal endophytes in D. thyrsiflorum were grouped into 11 genera, respectively. Fusarium was the dominant species of the two Dendrobium species in common. Antimicrobial activity of ethanol extract of fermentation broth of these fungi was explored using agar
diffusion test. 10 endophytic fungi in D. devonianum and 11 in D. thyrsiflorum exhibited antimicrobial activity against at least one pathogenic bacterium or fungus among 6 pathogenic microbes (Escherichia coli, Bacillus subtilis, Staphylococcus aureus, Candida albicans, Cryptococcus neoformans, and Aspergillus fumigatus). Out of the fungal endophytes isolated from D. devonianum and D. thyrsiflorum, Phoma displayed strong inhibitory activity (inhibition zones in diameter >20 mm) against pathogens. Epicoccum nigrum from D. thyrsiflorum exhibited antibacterial activity even stronger than ampicillin sodium. Fusarium isolated from the two Dendrobium species was effective against the pathogenic bacterial as well as fungal pathogens. The study reinforced the assumption that
endophytic fungi isolated from different Dendrobium species could be of potential antibacterial or antifungal resource. 相似文献
14.
Field observations and inoculation experiments revealed that Uromyces appendiculatus var. azukicola has an autoecious and macrocyclic life cycle and produces spermogonia, aecia, uredinia, and telia on Vigna angularis var. angularis and V. angularis var. nipponensis. From inoculation experiments, it was suggested that this rust fungus has different host relationships from other varieties. Morphological examinations revealed that the characteristics of urediniospores and teliospores are different among varieties, although aeciospores are morphologically similar to each other.Contribution no. 182, Laboratory of Plant Parasitic Mycology, Institute of Agriculture and Forestry, University of Tsukuba, Japan 相似文献
15.
Isolations were made to determine the fungal symbionts colonizing Platypus quercivorus beetle galleries of dead or dying Quercus laurifolia, Castanopsis cuspidata, Quercus serrata, Quercus crispula, and Quercus robur. For these studies, logs from oak wilt-killed trees were collected from Kyoto Prefecture, Japan. Fungi were isolated from
the: (1) entrances of beetle galleries, (2) vertical galleries, (3) lateral galleries, and (4) the larval cradle of P. quercivorus in each host tree. Among the fungus colonies which appeared on YM agar plates, 1,219 were isolated as the representative
isolates for fungus species inhabiting in the galleries based on their cultural characteristics. The validity of the visual
classification of the fungus colonies was checked and if necessary properly corrected using microsatellite-primed PCR fingerprints.
The nucleotide sequence of the D1/D2 region of the large subunit nuclear rRNA gene detected 38 fungus species (104 strains)
of which three species, i.e., Candida sp. 3, Candida kashinagacola (both yeasts), and the filamentous fungus Raffaelea quercivora were isolated from all the tree species. The two yeasts were most prevalent in the interior of galleries, regardless of host
tree species, suggesting their close association with the beetle. A culture-independent method, terminal restriction fragment
length polymorphism (T-RFLP) analysis was also used to characterize the fungus flora of beetle galleries. T-RFLP patterns
showed that yeast species belonging to the genus Ambrosiozyma frequently occurred on the gallery walls along with the two Candida species. Ours is the first report showing the specific fungi inhabiting the galleries of a platypodid ambrosia beetle. 相似文献
16.
Circa 1900, a farmer from the eastern US planted 11 American chestnut (Castanea dentata) seeds on a newly established farm near West Salem in western Wisconsin. These trees were very successful, producing a large
stand of over 6,000 trees. Since this area is well outside the natural range of chestnut, these trees remained free from chestnut
blight until 1987. In the West Salem stand, chestnuts are the dominant species of a mixed forest community, reminiscent of
the chestnut–oak ecosystems of pre-1900 Appalachia. To identify putative mycorrhizal associates of chestnut in this unique
forest, our approach was twofold: (1) an extensive fruiting body survey was conducted for four seasons that yielded approximately
100 putative mycorrhizal species and (2) a belowground molecular approach was used to generate DNA sequences of the internal
transcribed spacer region from ectomycorrhizae. Unexpectedly, chestnut did not appear to be the dominant underground ectomycorrhizal-forming
plant species. This study highlights the need to identify the plant host species when conducting belowground molecular-based
surveys and provides preliminary identification of ectomycorrhizal fungi associated with a disjunct stand of American chestnut.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
17.
Parasitic plants in the Orobanchaceae invade roots of neighboring plants to rob them of water and nutrients. Triphysaria is facultative parasite that parasitizes a broad range of plant species including maize and Arabidopsis. In this paper we describe transient and stable transformation systems for Triphysaria
versicolor Fischer and C. Meyer. Agrobacterium
tumefaciens and Agrobacterium
rhizogenes were both able to transiently express a GUS reporter in Triphysaria seedlings following vacuum infiltration. There was a correlation between the length of time seedlings were conditioned in
the dark prior to infiltration and the tissue type transformed. In optimized experiments, nearly all of the vacuum infiltrated
seedlings transiently expressed GUS activity in some tissue. Calluses that developed from transformed tissues were selected
using non-destructive GUS staining and after several rounds of in vivo GUS selection, we recovered uniformly staining GUS
calluses from which roots were subsequently induced. The presence and expression of the transgene in Triphysaria was verified using genomic PCR, RT PCR and Southern hybridizations. Transgenic roots were also obtained by inoculating A. rhizogenes into wounded Triphysaria seedlings. Stable transformed roots were identified using GUS staining or fluorescent microscopy following transformation
with vectors containing GFP, dsRED or EYFP. Transgenic roots derived from both A.
tumefaciens and A.
rhizogenes transformations were morphologically normal and developed haustoria that attached to and invaded lettuce roots. Transgenic
roots also remained competent to form haustoria in response to purified inducing factors. These transformation systems will
allow an in planta assessment of genes predicted to function in plant parasitism.
Alexey Tomilov and Natalya Tomilova made an equal contribution in the paper. 相似文献
18.
Amanita concentrica sp. nov. is described from an evergreen broad-leaved forest of Chiba Prefecture with Castanopsis cuspidata var. sieboldii and Quercus glauca. The fungus is a medium to large, white to yellowish-white mushroom characterized by many pyramidal warts on pileus, striate
margin of pileus, distinct ascending concen-tric rings at upper part of stipe bulb, and inamyloid basidiospores. It is considered
to belong to the section Amanita.
Received: March 30, 2001 / Accepted: October 1, 2001 相似文献
19.
Milan Gryndler Zuzana Egertová Lucie Soukupová Hana Gryndlerová Jan Borovička Hana Hršelová 《Mycological Progress》2010,9(1):27-36
Seventeen isolates of Entoloma clypeatum, a fungus associated with rosaceous woody plants and suspected to act as a root pathogen, were obtained from fruit-bodies
collected at 7 localities in the Czech Republic. The fungus grew best on the medium supplied with cellobiose. The growth of
E. clypeatum was inhibited by fungicide preparation Ridomil Gold MZ 68WP. A part of the LSU rRNA gene of 11 selected isolates was sequenced
and two reverse primers recognizing the sequence motifs in the LSU rRNA gene of E. clypeatum and other related species associated with rosaceous woody plants were designed. One of these primers, NL4EC2, showed high
specificity towards DNA of Entoloma spp. of interest and may be used for detection of these organisms in soil, in roots or in the substrate where the fruit trees
are cultivated. The results of in vitro inoculation experiment suggest a resistance of roots of young Prunus domestica plants to colonization by Entoloma clypeatum, and the fungus could be detected only in the surrounding substrate. We were able to detect Entoloma spp. in soil and in roots of Prunus avium but only if the fructification of the fungus occurred at the locality. The method is robust towards the false positive detection
caused by nonspecific amplification of DNA of other soil microorganisms. 相似文献
20.
Akiyoshi Yamada Daisei Kitamura Masanobu Setoguchi Yosuke Matsuda Yasushi Hashimoto Norihisa Matsushita Masaki Fukuda 《Ecological Research》2008,23(6):983-993
Monotropastrum humile is nearly lacking in chlorophyll and obtains its nutrients, including carbon sources, from associated mycorrhizal fungi.
We analyzed the mycorrhizal fungal affinity and species diversity of M. humile var. humile mycorrhizae to clarify how the plant population survives in Japanese forest ecosystems. We classified 78 samples of adult
M. humile var. humile individuals from Hokkaido, Honshu, and Kyusyu Islands into 37 root mycorrhizal morphotypes. Of these, we identified 24 types
as Russula or Lactarius fungal taxa in the Russulaceae, Basidiomycetes, but we could not identify the remaining 13 types as to their genus in the
Basidiomycetes. The number of fungal species on M. humile var. humile was the highest in the plant subfamily. The diversity of fungal species revealed its increased trends in natural forests
at the stand level, fagaceous vegetation, and cool-temperate climate. The most frequently observed fungus colonized mainly
samples collected from sub-alpine forests; the second most frequently observed fungus colonized samples collected from sub-alpine
to warm-temperate forests. These results suggest that Japanese M. humile populations are associated with specific but diverse fungi that are common ectomycorrhizal symbionts of various forest canopy
trees, indicating a tripartite mycorrhizal relationship in the forest ecosystem. 相似文献