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Mycelium

About: Mycelium is a research topic. Over the lifetime, 8923 publications have been published within this topic receiving 170993 citations.


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Journal ArticleDOI
TL;DR: The effect of three different nitrogen sources on the growth of external ectomycorrhizal mycelium was studied in Perspex micorocosms and the shoot to root ratio generally increased, mainly as a result of increased shoot growth.
Abstract: The effect of three different nitrogen sources on the growth of external ectomycorrhizal mycelium was studied in Perspex micorocosms. Nonsterile peat was used as substrate. Five different fungal isolates growing in symbiosis with pine seedlings were investigated: two isolates of Paxillus involutus, one of Suillus bovinus and two unidentified ectomycorrhizal fungi isolated from ectomycorrhizal root tips. Three different nitrogen sources were used: ammonium as (NH4)2SO4, nitrate as NaNO3 and a complete nutrient solution (Ingestad 1979), and three different nitrogen concentrations, 1, 2 or 4 mg N/g dry wt. of peat. The mycelial growth of all fungi was found to be negatively affected by the nitrogen amendments, although the sensitivity to nitrogen varied between the isolates. One of the unidentified isolates was extremely sensitive and growth was completely inhibited by all nitrogen treatments. In contrast, the growth of one of the P. involutus isolates was only slightly reduced by the nitrogen amendments. The different nitrogen sources all reduced growth, and since no significant difference was found between the nitrogen sources or between the different nitrogen concentrations the results were pooled to give one value that summarized the effect of nitrogen on mycelial growth. Thus, the mycelial growth of one of the two P. involutus isolates was reduced to approximately 80% of the growth in the control, the other P. involutus and one of the unidentified fungi, vgk 2 89.10, were reduced to 40–50% of the control growth, S. bovinus to 30% of the control and the most sensitive fungus, the unidentified isolate vg 1 87.10, was reduced to 3% of the growth in the control treatment. In all experiments, the shoot to root ratio generally increased, mainly as a result of increased shoot growth.

121 citations

Journal ArticleDOI
TL;DR: Detailed evidence is provided from a natural system that AMF taxa are differentially allocated among soil mycelium, soil spores and colonized root propagules and this has important implications for interpreting AMF diversity surveys and designing applications of AMF in vegetation restoration.
Abstract: Summary Arbuscular mycorrhizal fungi (AMF) are essential constituents of most terrestrial ecosystems. AMF species differ in terms of propagation strategies and the major propagules they form. This study compared the AMF community composition of different propagule fractions ‐ colonized roots, spores and extraradical mycelium (ERM) ‐ associated with five Mediterranean plant species in Sierra de Baza Natural Park (Granada, Spain). AMF were identified using 454 pyrosequencing of the SSU rRNA gene. A total of 96 AMF phylogroups [virtual taxa (VT)] were detected in the study site, including 31 novel VT.After per-sample sequencing depth standardization, 71 VT were recorded from plant roots, and 47 from each of the spore and ERM fractions. AMF communities differed significantly among the propagule fractions, and the root-colonizing fraction differed among host plant species. Indicator VT were detected for the root (13 Glomus VT), spore (Paraglomus VT281, VT336, Pacispora VT284) and ERM (Diversispora VT62) fractions. This study provides detailed evidence from a natural system that AMF taxa are differentially allocated among soil mycelium, soil spores and colonized root propagules. This has important implications for interpreting AMF diversity surveys and designing applications of AMF in vegetation restoration.

121 citations

Journal ArticleDOI
17 Jan 1953-Nature
TL;DR: It was shown, by using the isotope technique, that hyphæ of Boletus variegatus (Sw.) Fr.
Abstract: IN a previous paper from this Institute1 it was shown, by using the isotope technique, that hyphae of Boletus variegatus (Sw.) Fr. in mycorrhizal connexion with pine seedlings transfer nitrogen from a solution of an ammonium salt to the roots. The labelled nitrogen was added as ammonium nitrate containing the stable isotope nitrogen-15 in the ammonium group. By a special arrangement, only the mycelium was exposed to the isotope, and then the amounts of nitrogen-15 were measured in different parts of the seedlings.

121 citations

Journal ArticleDOI
TL;DR: The results show that differences in mycelial size among AMF families may contribute to variation in host responsiveness to AMF, but other factors are also important.
Abstract: Plants differ in the benefit they receive from an association with arbuscular mycorrhizal fungi (AMF) but it is unclear what factors determine host response. We tested whether this difference is due in part to differences among AMF families (Glomaceae, Gigasporaceae, and Acaulosporaceae) in the size of their mycelium. For example, an AMF with a large mycelium might be better able to transfer nutrients to its host. Alternatively, the large mycelium might present a large carbon drain for the host. It might also be the location of AMF mycelium that is important: whether it occurs in the root or in the soil. In a greenhouse experiment, four different host plant species were inoculated with each of 21 AMF isolates representing different mycelial sizes and we measured both host plant biomass and foliar phosphorus concentration over 12 weeks. AMF family significantly affected host biomass with larger internal mycelia conferring greater host benefit. However, both intra-family variation in AMF effect and host identity also influenced host response. For foliar P, AMF family did not affect host response significantly. Our results show that differences in mycelial size among AMF families may contribute to variation in host responsiveness to AMF, but other factors are also important.

120 citations

Journal ArticleDOI
TL;DR: Most antibiotic-producing isolates possess red and white colour, and strong antibiosis was exhibited against Streptomyces scabies, Staphylococcus aureus and Bacillus subtilis, while only 14 and 8% of isolates displayed an activity against Escherichia coli and Verticillium dahliae respectively.
Abstract: During an investigation on actinomycetes from rhizospheric soils from Moroccan habitats, 131 streptomycetes were recovered, morphologically characterized and assessed for their antimicrobial activity. Eleven isolates were characterized by the absence of an aerial mycelium. According to the colour of aerial mycelium, the rest were grouped into seven main classes, namely, grey, yellow, cream, white, green, red and polymorphic colours (pink, orange or violet). The grey colour class dominated (40%) and the red one was found only in rhizospheric soil of the Moroccan endemic plant Argania spinosa. About one third of the isolates (34%) produced soluble pigments of various colours and 14% produced melanoid pigments. Most of the isolates (83%) were active against one or more of the organisms tested (one gram-negative bacterium, three gram-positive bacteria, three yeasts and two filamentous fungi). Most antibiotic-producing isolates possess red and white colour. Strong antibiosis was exhibited against Streptomyces scabies, Staphylococcus aureus and Bacillus subtilis (75, 68 and 60% respectively), while only 14 and 8% of isolates displayed an activity against Escherichia coli and Verticillium dahliae respectively.

120 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
20242
2023951
20221,628
2021187
2020287
2019295