首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
Relationships between physico-chemical factors of waters, riparian vegetation, altitude and species richness of the hyphomycete communities in six rivers and a sulfur spring in the Western Ghats of Karnataka were analysed statistically. Linear regression and correlation between log fungal species and riparian vegetation was highly significant. The similarity in the fungal diversity between different rivers and the sulphur spring was evaluated by Sorensen's index. Generally, the indices of similarity in the mycoflora between the streams were high. However, in the streams of Lakya, Bhadra, Ranganathittu bird sanctuary and the sulfur spring the indices of similarity were low compared with the rest of the water systems. The low pH, low oxygen concentration, hardness, high iron, high temperature and sulfide contents of the waters of these streams are thought to be the reasons for the differences in these streams. Anguillospora longissima, Helicomyces roseus, Lunulospora curvula, Triscelophorus monosporus and Wiesneriomyces laurinus were found to be the most abundant species.  相似文献   

2.
The bark beetle Ips typographus has different hibernation environments, under the bark of standing trees or in the forest litter, which is likely to affect the beetle-associated fungal flora. We isolated fungi from beetles, standing I. typographus-attacked trees, and forest litter below the attacked trees. Fungal identification was done using cultural and molecular methods. The results of the two methods in detecting fungal species were compared. Fungal communities associated with I. typographus differed considerably depending on the hibernation environment. In addition to seven taxa of known ophiostomoid I. typographus-associated fungi, we detected 18 ascomycetes and anamorphic fungi, five wood-decaying basidomycetes, 11 yeasts, and four zygomycetes. Of those, 14 fungal taxa were detected exclusively from beetles that hibernated under bark, and six taxa were detected exclusively from beetles hibernating in forest litter. The spruce pathogen, Ceratocystis polonica, was detected occasionally in bark, while another spruce pathogen, Grosmannia europhioides, was detected more often from beetles hibernating under the bark as compared to litter. The identification method had a significant impact on which taxa were detected. Rapidly growing fungal taxa, e.g. Penicillium, Trichoderma, and Ophiostoma, dominated pure culture isolations; while yeasts dominated the communities detected using molecular methods. The study also demonstrated low frequencies of tree pathogenic fungi carried by I. typographus during its outbreaks and that the beetle does not require them to successfully attack and kill trees.  相似文献   

3.
We mapped filamentous fungal association with mechanically “hard” and “soft” woody litter naturally deposited in a stream of the Western Ghats of India. Using a durometer (rubber hardness tester), the toughness of surface of wood collected from stream was determined by considering durometer reading from 60–72 to 30–37 as hardwood and softwood, respectively. From each wood (1.5 cm diameter), two segments each of 3 cm length were excised and vertically cut into nine sections comprising eight marginal and one central section. From three stream locations, hardwood and softwood sections were assessed for the occurrence of lignicolous and Ingoldian fungi. A first set of wood sections was incubated in damp chambers up to 4 months with periodical screening (every 2 weeks) for lignicolous fungi. Another set was incubated in bubble chambers up to 72 h to ascertain colonization of Ingoldian fungi. In hardwood sections, 17 lignicolous fungi (ascomycetes, four; mitosporic fungi, 13; mean, 6.8; range, 6–8/section) and ten Ingoldian fungi (mean, 2; range, 0–4/section) comprising nine lignicolous (11.1–40.7%) and three Ingoldian (11.1–14.8%) fungi as core-group taxa were recovered. In softwood, ten lignicolous fungi (ascomycetes, 0; mitosporic fungi, ten; mean, 3.8; range, 2–5/section) and 26 Ingoldian fungi (mean, 8.1; range, 5–10/section) comprising six lignicolous (11.1–85.2%) and 12 Ingoldian (11.1–88.9%) fungi as core-group taxa were recovered. The ratio of lignicolous fungi/Ingoldian fungi was higher in hardwood than softwood (1.7 vs. 0.4). The spore output of Ingoldian fungi was higher in softwood (mean, 901 g−1; range, 80–2546 g−1) than hardwood (mean, 21 g−1; range, 0–140 g−1). The Shannon diversity of lignicolous fungi was higher in hardwood than softwood (3.604 vs. 2.665), whereas it was opposite for Ingoldian fungi (3.116 vs. 3.918). The overall fungal diversity was higher in softwood than hardwood (4.413 vs. 4.219). The range of Jaccard’s index of similarity among wood sections was higher in lignicolous fungi (8–71% and 13–75%) than Ingoldian fungi (0–50% and 8–55%) in hardwood and softwood. The rarefaction indices of expected number of taxa against hardwood sections revealed higher and persistent lignicolous fungi than the Ingoldian fungi, while the Ingoldian fungi were persistent in softwood sections, although they were lower than lignicolous fungi. Our study demonstrated the dominance of lignicolous fungi and Ingoldian fungi in hardwood and softwood, respectively.  相似文献   

4.
Because mangrove plant species are a valuable source of useful metabolites, their endophytes have gained more importance. Randomly sampled surface-sterilized whole root segments of four mangrove plant species, Acanthus ilicifolius, Avicennia officinalis, Rhizophora mucronata, and Sonneratia caseolaris from the mangroves of Udyavara (Karnataka) on the west coast of India, were characterized for fungal communities by direct plating, damp chamber, and bubbling chamber incubation methods. The richness of endophytic fungal species from whole root segments after direct plating and damp chamber incubation was greatest for R. mucronata than for other plants (18 vs. 8-13). Incubation of whole root segments in bubbling chambers yielded conidia of two freshwater hyphomycetes: Mycocentrospora acerina (in Avicennia officinalis) and Triscelophorus acuminatus (in R. mucronata and in S. caseolaris). Surface-sterilized whole root and root bark segments of R. mucronata sampled from the mid-tide level on direct plating yielded more fungi than that of the root segments sampled from low-tide and high-tide levels. The greatest number of isolates, species richness, and diversity of fungi were shown by the whole root segments of R. mucronata from the mid-tide level. Rarefaction indices also revealed the highest expected number of species out of 150 random isolations from the mid-tide level samples of whole root and root bark segments of R. mucronata. The present study showed that fungi in mangrove roots are composed of a consortium of soil, marine, and freshwater fungi.  相似文献   

5.
Temperature is a key factor in determining the structure and performance of fungal assemblages on decomposing plant litter in streams. However, little is known of how temperature affects interspecific relationships among fungi. We compared the growth of four aquatic hyphomycetes co-occurring in temperate streams, in monocultures and all species combinations when exposed to five temperatures from 11 to 27 °C. In monocultures, maximum growth rates of Heliscus submersus, Lunulospora curvula and Varicosporium elodeae occurred at 27 °C whereas Articulospora tetracladia had the lowest growth rate. At 27 °C, the increase in species diversity had no effect on the growth of V. elodeae, increased the growth of H. submersus and L. curvula, and decreased the growth of A. tetracladia. Results suggest that within a species' optimal temperature range the growth of that species increases with higher fungal diversity, while outside this range growth decreases with diversity.  相似文献   

6.
Figueira D  Barata M 《Mycologia》2007,99(1):20-23
The occurrence of marine fungi associated with, pieces of wood, driftwood and dead plant stems, in the intertidal zone of two sandy beaches on the Portuguese west coast, was surveyed for 5 mo. Out of 90 samples scanned 70% had sporulating marine fungi. Thirty-five marine fungal taxa were identified (27 Ascomycota, six anamorphic fungi and two unidentified taxa), out of which 11 species were common to both beaches. Most taxa were infrequent (< or =10%), with the exception of Kirschsteiniothelia maritima (10-20%). The average number of fungi per sample was 0.91 for both beaches. Fifteen species are new records for Portugal. Samples were examined immediately after they were taken to the laboratory, as well as after incubation in moist chamber, for up to 10 mo.  相似文献   

7.
Ascomycota are among the fungi that cause serious willow diseases in all natural habitats worldwide. This study was conducted to determine if basket willow used in green wall structures (GWS) built of willow stems were infected by potentially important fungal diseases or their antagonists in urban areas of eastern Canada. In total, 13 different phenotypic genera belonging to eight families of ascomycetous fungi were isolated and identified according to their sexual and/or asexual forms. Venturia pathogenic species complex were represented by three different anamorphs: Fusicladium, Fusicladium-Cladosporium, and Pollaccia as anamorph. They were responsible for the highest incidence value on leaves (IF > 15%). Cryptodiaporthe, Drepanopeziza, and Glomerella dominated on bark (IF > 5%). A significantly higher incidence value of fungal communities was found on first year than on second year GWS. The correspondence analysis using χ2 distance showed that communities of potentially pathogenic species are closely related to diseased plants, while healthy plants often contain biocontrol species such as Cladobotryum mycoparasite on healthy bark and Alternaria sp. antagonist on healthy leaves. The phylogenetic positions of the different fungal taxa and their relationship have been revealed by use of PCR amplified internal transcriber spacer (ITS) region of rDNA.  相似文献   

8.
In the more than twenty years in which long-term canopy research has been conducted, mycology has been largely disregarded. Our studies using a construction crane to gain access to the canopy of a forest in Leipzig, Germany are the first long term investigations assessing the diversity and ecology of wood-decaying fungi in a canopy. Thirty-seven individuals of nine different tree species with a large amount of dead wood were selected. Sampling focussed on the four most prominent tree species Acer pseudoplatanus, Fraxinus excelsior, Quercus robur and Tilia cordata. In the years 2002 and 2003 dead wood was collected in different canopy strata. Dead branches were removed and stored for two weeks in open boxes with high humidity to allow growth of fructifications in the laboratory. 118 different taxa were identified (108 species, 77 genera). Corticioid fungi (e.g., of Corticiaceae, Stereaceae, Hymenochaetaceae) dominated the fungal composition with 37 species, pyrenomycetes were present with 18 species. Agaric fungi (Agaricales and Cortinariales) were scarce. Species with minute basidiomes dominated the fungal composition of this systematic group. Agarics with larger sporomes were found only once and were restricted to strongly decayed branches in shaded canopy areas. Concerning species richness and fungal composition the four tree species mentioned above differed remarkably. As expected, many fungi that grew on bark or slightly decayed wood showed a distinct host and substratum specifity. It is noteworthy that fungi which are purportedly to be non-specific were found on single tree species only.  相似文献   

9.
Fungal endophytes were isolated from Crataeva magna, a medicinal plant growing along the streams and rivers, constituting riparian vegetation in Karnataka, southern India. Fresh bark and twig pieces were used for the isolation using standard methods. Ninety-six endophytic fungal isolates were isolated from 800 bark and twig segments. Mitosporic fungi represented as a major group (85%) followed by zygomycetes (10%) and ascomycetes (5%). Bark samples contained more endophytes than twig samples. Verticillium, Nigrospora oryzae and Fusarium verticilloides were the dominant fungal endophytes.  相似文献   

10.
Abstract. Populations of Carex curvula ssp. curvula, C. curvula ssp. rosae and their intermediate form were investigated in the Central Alps over a three-year period. The closely related taxa showed a different dominance behaviour in their respective communities. This may be caused by different growth strategies and a different reproduction biology. Therefore, the main aim of the study was to compare the demography of the three taxa. Shoot and leaf turnover, flower and seed production and population half-lives were determined. Differences in growth dynamics were less pronounced between the two species of Carex curvula than between these taxa and their intermediate form which showed the highest shoot turnover, highest number of fertile inflorescences and highest number of seeds per inflorescence. Carex curvula ssp. rosae showed a slightly higher shoot and leaf production but a lower reproduction capacity than Carex curvula ssp. curvula. Recruitment of populations of the three Carex-forms was only by vegetative shoots. Flowering had a striking effect on the shoot dynamics of the species grown in the grassland sites: up to about 70 % of all dead shoots could be identified as dead flowering shoots from the previous year. The different dominance behaviour of the three taxa could not be explained by their demographical features. Interspecific interactions and the occurrence of microniches might affect the growth and reproduction processes of the taxa.  相似文献   

11.
A prevailing paradigm in forest ecology is that wood‐boring beetles facilitate wood decay and carbon cycling, but empirical tests have yielded mixed results. We experimentally determined the effects of wood borers on fungal community assembly and wood decay within pine trunks in the southeastern United States. Pine trunks were made either beetle‐accessible or inaccessible. Fungal communities were compared using culturing and high‐throughput amplicon sequencing (HTAS) of DNA and RNA. Prior to beetle infestation, living pines had diverse fungal endophyte communities. Endophytes were displaced by beetle‐associated fungi in beetle‐accessible trees, whereas some endophytes persisted as saprotrophs in beetle‐excluded trees. Beetles increased fungal diversity several fold. Over forty taxa of Ascomycota were significantly associated with beetles, but beetles were not consistently associated with any known wood‐decaying fungi. Instead, increasing ambrosia beetle infestations caused reduced decay, consistent with previous in vitro experiments that showed beetle‐associated fungi reduce decay rates by competing with decay fungi. No effect of bark‐inhabiting beetles on decay was detected. Platypodines carried significantly more fungal taxa than scolytines. Molecular results were validated by synthetic and biological mock communities and were consistent across methodologies. RNA sequencing confirmed that beetle‐associated fungi were biologically active in the wood. Metabarcode sequencing of the LSU/28S marker recovered important fungal symbionts that were missed by ITS2, though community‐level effects were similar between markers. In contrast to the current paradigm, our results indicate ambrosia beetles introduce diverse fungal communities that do not extensively decay wood, but instead reduce decay rates by competing with wood decay fungi.  相似文献   

12.
Bark represents a unique microbial habitat. Revealing the interactions among bark-associated microbes is important for understanding their diversity, stability, and function, and how core microbiome influences the health and production of the host plant. We used amplicon sequencing of bark from the medicinal plant Eucommia ulmoides collected across nine distinct biogeographical regions in China, and comprehensively analyzed the diversity, rare biosphere and core taxa of bark fungi. The co-occurrence network results showed significant differences in the compositions of core mycobiota in E. ulmoides bark between the nine regions. Ecological factors (e.g., temperature and rainfall) were crucial determinants of differences in the unique core mycobiota of E. ulmoides from different regions. The metacommunity-scale network indicated that Cladosporium, Alternaria, and Teratosphaeria were core fungal taxa of E. ulmoides bark. Moreover, some core fungal taxa included rare taxa in particular local communities which, despite their relatively low abundance, may play a significant role in the community structure of E. ulmoides bark.  相似文献   

13.
The fungal species from rhizosphere and rhizoplane of perennial grasses of the Western Ghats of India were studied for their pathogenicity, antagonism in vitro, substrate and root colonization abilities, rhizosphere competence, growth in different soil pH and inoculum shelf-life. Out of 138 non-pathogenic fungal isolates tested, 85 were antagonistic in vitro to chilli anthracnose pathogen Colletotrichum capsici. Fifteen isolates with >60% inhibition zone to pathogen culture had saprophytic and root and rhizosphere colonization abilities. The sorghum grain inocula of test antagonistic fungi- Fusarium oxysporum, Chaetomium globosum and Trichoderma harzianum had the shelf-life of 90 days at 20?±?2?°C and required optimum soil pH of 6.5. The above fungal isolates when tested for biocontrol of anthracnose disease in greenhouse and field caused reduction in seedling mortality and decreased disease incidence and severity at various plant growth stages and significant reduction in chilli fruit and seed infection. The test antagonistic fungi promoted seedling and mature plant growth and increased fruit and seed yield. Populations of these antagonistic fungi were fairly high in chilli rhizosphere at harvest. The present study indicated that antagonistic fungi from grass rhizosphere and rhizoplane could be used to control anthracnose and promote plant growth, and increase yield of chilli in field.  相似文献   

14.
The climbing orchid Erythrorchis altissima is the largest mycoheterotroph in the world. Although previous in vitro work suggests that E. altissima has a unique symbiosis with wood‐decaying fungi, little is known about how this giant orchid meets its carbon and nutrient demands exclusively via mycorrhizal fungi. In this study, the mycorrhizal fungi of E. altissima were molecularly identified using root samples from 26 individuals. Furthermore, in vitro symbiotic germination with five fungi and stable isotope compositions in five E. altissima at one site were examined. In total, 37 fungal operational taxonomic units (OTUs) belonging to nine orders in Basidiomycota were identified from the orchid roots. Most of the fungal OTUs were wood‐decaying fungi, but underground roots had ectomycorrhizal Russula. Two fungal isolates from mycorrhizal roots induced seed germination and subsequent seedling development in vitro. Measurement of carbon and nitrogen stable isotope abundances revealed that E. altissima is a full mycoheterotroph whose carbon originates mainly from wood‐decaying fungi. All of the results show that E. altissima is associated with a wide range of wood‐ and soil‐inhabiting fungi, the majority of which are wood‐decaying taxa. This generalist association enables E. altissima to access a large carbon pool in woody debris and has been key to the evolution of such a large mycoheterotroph.  相似文献   

15.
Among wood‐degrading fungi, lineages holding taxa that selectively metabolize carbohydrates without significant lignin removal (brown rot) are polyphyletic, having evolved multiple times from lignin‐removing white rot fungi. Given the qualitative nature of the ‘brown rot’ classifier, we aimed to quantify and compare the temporal sequence of carbohydrate removal among brown rot clades. Lignocellulose deconstruction was compared among fungi using distinct plant substrates (angiosperm, conifer, grass). Specifically, aspen, pine and corn stalk were harvested over a 16‐week time series from microcosms containing Gloeophyllum trabeum, Fomitopsis pinicola, Ossicaulis lignatilis, Fistulina hepatica, Serpula lacrymans, Wolfiporia cocos or Dacryopinax sp. After quantifying plant mass loss, a thorough compositional analysis was complemented by a saccharification test to determine wood cell wall accessibility. Mass loss and accessibility varied depending on fungal decomposer and substrate, and trajectories of loss for hemicellulosic components and cellulose differed among plant tissue types. At any given stage of decomposition, however, lignocellulose accessibility and the fraction remaining of carbohydrates and lignin within a plant tissue type were generally the same, regardless of fungal isolate. This suggests that the sequence of plant component removal at this typical scale of characterization is shared among these brown rot lineages, despite their diverse genomes and secretomes.  相似文献   

16.
We studied extent and type of arbuscular mycorrhizal (AM) and septate endophytic (SE) fungal associations in five lycophytes and 50 ferns collected from Eastern and Western Ghats regions. Of the 54 species and one variety (belonging to 31 genera) examined; 54 taxa had AM association and AM fungal structures were absent in Marsilea quadrifolia. This is the first report of AM and SE fungal status for 26 species each. Of the 55 taxa examined, AM morphology has been evaluated for the first time in 51 species. The hydrophytic fern Salvinia molesta was mycorrhizal and non-mycorrhizal at different sites. All the epiphytic and saxicolous species examined were mycorrhizal. The percentage of AM colonization ranged from 22.23 (Christella parasitica) to 82.20 (Adiantum lunulatum) in ferns and 53.46 (Selaginella bryopteris) to 84.34 (Selaginella sp.) in lycophytes. Epiphytic life-forms had the maximum average AM colonization levels, whereas aquatic life-forms had the minimum colonization levels. The percentage root length colonized by septate fungi ranged between 0.59 in Ophioglossum reticulatum and 16.36 in Pteris pellucida. The root length with AM and SE fungal structures as well as their total colonization significantly varied among the taxa examined. Most of the lycophytes and ferns had intermediate-type of AM morphology with a few exhibiting Paris-type. AM fungal spore numbers ranged from 1.0 (Angiopteris evecta, Pteridium aquilinum) to (Nephrolepis exaltata) 9.3 spores per 25 g soil and varied significantly among taxa. AM fungal spore morphotypes belonging to Claroideoglomus, Funneliformis, Glomus and Rhizophagus were recorded.  相似文献   

17.
Assessment of soil fungal communities using pyrosequencing   总被引:1,自引:0,他引:1  
Pyrosequencing, a non-electrophoretic method of DNA sequencing, was used to investigate the extensive fungal community in soils of three islands in the Yellow Sea of Korea, between Korea and China. Pyrosequencing was carried out on amplicons derived from the 5′ region of 18S rDNA. A total of 10,166 reads were obtained, with an average length of 103 bp. The maximum number of fungal phylotypes in soil predicted at 99% similarity was 3,334. The maximum numbers of phylotypes predicted at 97% and 95% similarities were 736 and 286, respectively. Through phylogenetic assignment using BLASTN, a total of 372 tentative taxa were identified. The majority of true fungal sequences recovered in this study belonged to the Ascomycota (182 tentative taxa in 2,708 reads) and Basidiomycota (172 tentative taxa in 6,837 reads). The predominant species of Ascomycota detected have been described as lichen-forming fungi, litter/wood decomposers, plant parasites, endophytes, and saprotrophs: Peltigera neopolydactyla (Lecanoromycetes), Paecilomyces sp. (Sordariomycetes), Phacopsis huuskonenii (Lecanoromycetes), and Raffaelea hennebertii (mitosporicAscomycota). The majority of sequences in the Basidiomycota matched ectomycorrhizal and wood rotting fungi, including species of the Agaricales and Aphyllophorales, respectively. A high number of sequences in the Thelephorales, Boletales, Stereales, Hymenochaetales, and Ceratobasidiomycetes were also detected. By applying high-throughput pyrosequencing, we observed a high diversity of soil fungi and found evidence that pyrosequencing is a reliable technique for investigating fungal communities in soils.  相似文献   

18.
We isolated ophiostomatoid fungi from bark beetles infesting Pinus densiflora and their galleries at 24 sites in Japan. Twenty-one ophiostomatoid fungi, including species of Ophiostoma, Grosmannia, Ceratocystiopsis, Leptographium, and Pesotum, were identified. Among these, 11 species were either newly recorded in Japan or were previously undescribed species. Some of these fungal species were isolated from several bark beetles, but other species were isolated from only a particular beetle species. Thus, it is suggested that some ophiostomatoid fungi have specific relationships with particular beetle species. In addition, fungus-beetle biplots from redundancy analysis (RDA) summarizing the effects of beetle ecological characteristics suggested that the association patterns between bark beetles and the associated fungi seemed to be related to the niches occupied by the beetles.  相似文献   

19.
The effect of zinc on leaf decomposition by aquatic fungi was studied in microcosms. Alder leaf disks were precolonized for 15 days at the source of the Este River and exposed to different zinc concentrations during 25 days. Leaf mass loss, fungal biomass (based on ergosterol concentration), fungal production (rates of [1-14C]acetate incorporation into ergosterol), sporulation rates, and species richness of aquatic hyphomycetes were determined. At the source of the Este River decomposition of alder leaves was fast and 50% of the initial mass was lost in 25 days. A total of 18 aquatic hyphomycete species were recorded during 42 days of leaf immersion. Articulospora tetracladia was the dominant species, followed by Lunulospora curvula and two unidentified species with sigmoid conidia. Cluster analysis suggested that zinc concentration and exposure time affected the structure of aquatic hyphomycete assemblages, even though richness had not been severely affected. Both zinc concentration and exposure time significantly affected leaf mass loss, fungal production and sporulation, but not fungal biomass. Zinc exposure reduced leaf mass loss, inhibited fungal production and affected fungal reproduction by either stimulating or inhibiting sporulation rates. The results of this work suggested zinc pollution might depress leaf decomposition in streams due to changes in the structure and activity of aquatic fungi.  相似文献   

20.
A new species of Clausena, C. agasthyamalayana is described and illustrated from the southern Western Ghats, Kerala, India. It is similar to C. indica but differs from it being of dwarf habit, and having greenish–black bark, smaller and fewer leaflets, obovate and coriaceous leaves with obtuse or emarginated apex, elliptic and obtuse petals, oblong‐cordate anthers, consistently 4‐locular ovary with 2 ovules in each chamber and ellipsoid fruits.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号