Progress 10/01/04 to 09/30/09
Outputs
OUTPUTS: Four additional peer reviewed papers and one commentary were published in the last nine months of the project for a total output of 39 publications over the five years of the project. The most recent additions continue the trend of reporting ecological research on ectomycorrhizal fungi and associated plant communities in top ecological journals. Participants in the project included nine PhD students (Nicole Hynson, Nick Rosenstock, Shannon Schechter, Valerie Wong, Nhu Nguyen, Jennifer Kerekes, Lisa Grubisha, Antonio Izzo, Tasha Hausmann); five have now graduated and gone on to postdoctoral (4), or faculty appointments (1), and two more are likely to graduate in the next year. Five postdoctoral associates (Peter Kennedy, Kabir Peay, Erik Lilleskov, Martin Bidartondo, and Else Vellinga) were trained and four have gone on to faculty positions. In addition, several visiting scientists participated in this work, and many undergraduates. Large numbers of presentations (both talks and posters) were presented at National and International meetings (e.g., Ecological Society of America, International Mycological Congress, Mycological Society of America), and at public venues (e.g., California Native Plant Soc., Amateur Mycological Societies). PARTICIPANTS: Participants in the project included nine PhD students (Nicole Hynson, Nick Rosenstock, Shannon Schechter, Valerie Wong, Nhu Nguyen, Jennifer Kerekes, Lisa Grubisha, Antonio Izzo, Tasha Hausmann); five have now graduated and gone on to postdoctoral (4), or faculty appointments (1), and two more are likely to graduate in the next year. Five postdoctoral associates (Peter Kennedy, Kabir Peay, Erik Lilleskov, Martin Bidartondo, and Else Vellinga) were trained and four have gone on to faculty positions. TARGET AUDIENCES: Much of work contributes to basic science and our target audience for this would be ecologists, microbiologist, mycologists, and foresters. In addition we have had long-term interactions with Park Service at Pt. Reyes National Seashore and have advised them on fungal issues many times. We also conduct public outreach through the local mushroom clubs such as the Bay Area Mycological Society, the Mycological Society of San Francisco, and the Sonoma Mycological Association. Members of the lab have given talks at all of these in the past year, and the Bay Area Mycological Society meets on the Berkeley campus. PROJECT MODIFICATIONS: Not relevant to this project.
Impacts
The most recent work demonstrated for the first time that ectomycorrhizal fungi can access ground water to facilitate their fruiting (1), that one of our most poisonous mushrooms in North America is a European introduction (2), that the distribution of a relatively rare orchid is dependent in part on the rarity of its fungal associate (3), and that a Pyrola aphylla is an exception to the rule that mycoheterotrophic plants specialize on a narrow range of fungi (4). Publications from the five-year period have been fundamental to the development of the investigations of mycoheterotrophic plants, competitive interactions among mycorrhizal fungi, and spore dispersal mechanisms and post-fire recolonization patterns of ectomycorrhizal fungi. As a result many of the papers produced from this project are already becoming highly cited. A Web of Science search shows that eight of the papers have each been cited more than 20 times, and 14 of them have been cited at least 14 times each. The training aspects of this work are also significant, in that five newly graduated PhD students and four postdoctoral associates have gone on in science. In addition public outreach work by Dr. Bruns and Dr. Vellinga has connected a specialized section of the general public to scientific research and lead to the first fungal survey of Pt. Reyes National Seashore.
Publications
- Lilleskov, E. A., Bruns, T. D., Dawson, T. E., Camacho, F. J. 2009. Water sources and controls on water-loss rates of epigeous ectomycorrhizal fungal sporocarps during summer drought. New Phytol. 182:483-494
- Pringle, A., Adams, R. I., Cross, H. B., and Bruns, T. D. 2009. The ectomycorrhizal fungus Amanita phalloides was introduced and is expanding its range on the west coast of North America. Mol. Ecol. 18: 817-833.
- McCormick M. K., Whigham D. F., ONeill J. P., Becker J. J., Werner S., Hanne N. Rasmussen H. N., Bruns, T. D., Taylor D. L. 2009. Abundance and distribution of Corallorhiza odontorhiza reflects variations in climate and ectomycorrhizae. Ecol Monogr. 79:619-635.
- Hynson, N.A. and Bruns, T. D. 2009. Evidence of a myco-heterotroph in the plant family Ericaceae that lacks mycorrhizal specificity. Proc. Roy. Acad. Sc. B 276:4053-4059
- Horton, T.R., Arnold, A.E., and Bruns, T. D. 2009. FESIN workshops at ESA - The mycelial network grows. Mycorrhiza 19:283-285.
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Progress 01/01/08 to 12/31/08
Outputs
OUTPUTS: In the last year we published two peer-reviewed papers and one solicited report, and Else Vellinga, a postdoctoral researcher in the lab, publish two additional peer-reviewed papers. Six other peer-reviewed papers were published or accepted for publication last year, but because they have 2009 dates they will be discussed next year. In addition Bruns organized the FESIN workshop at the Ecological Society of America meeting, and presented invited talks at this workshop, at a symposium of Mycological Society of America, at the Laboratoire Evolution et Diversite Biologique, Universite Paul Sabatier, Toulouse, France, at the New Phytologist meeting on Ectomycorrhizal Ecology at Montpellier France, and at the Mycological Society of San Francisco (an amateur, public group). PARTICIPANTS: The following PhD students are working on these parts of project: Nhu Nguyen works on spore establishment and bacterial interactions in ectomycorrhizal communities; Jennifer Kerekes works on structure of saprophytic fungal communities; Nicole Hynson works on mycoheterotrophic and mixotrophic members of the Pyrolaceae; Nicholas Rosenstock works on effects of cat ion depletion on ectomycorrhizal community structure; Valerie Wong on genomics of Rhizopogon salebrosus; Shannon Schecter works on arbuscular mycorrhizal communities and plant adaptation to serpentine soil. The following Postdoctoral researchers are working on these parts of the project: Kabir Peay is working on spore dispersal and establishment patterns in ectomycorrhizal communities; Dr. Else Vellinga is working on systematics of the Agaricaceae. TARGET AUDIENCES: Much of the work contributes primarily to basic science and our target audience for this would be ecologists, microbiologist, mycologists, and foresters. In addition we have had long-term interactions with the National Park Service at Pt. Reyes National Seashore and have advised them on fungal issues many times. We also conduct public outreach through the local mushroom clubs such as the Bay Area Mycological Society, the Mycological Society of San Francisco, and the Sonoma Mycological Association. Members of the lab have given talks at all of these in the past year, and the Bay Area Mycological Society meets on the Berkeley campus. PROJECT MODIFICATIONS: Not relevant to this project.
Impacts
The Schecter and Bruns Molecular Ecology paper demonstrated that ecotypes of the herb Collinsia sparsiflora associate with distinct arbuscular mycorrhizal fungi when they are on serpentine versus nonserpentine soil. This is an important result because it shows that part of the adaptation of plants to extreme soil conditions involves associating with a different set of root symbionts. Interestingly one of the fungi that occurred on the serpentine soil was previously known only from heavy-metal contaminated soil. Ongoing experiments will determine if this change in symbionts is necessary for the tolerance of these soils by the plants. The Peay et al BioScience paper reviews the field of fungal ecology and pointed out the tight linkage it has with molecular methodology. This is the first broad review on the field since the advent of molecular ecology, and it is likely to have a significant impact on the field. The Fungal Environmental Sampling and Informatics Network (FESIN) continues to help shape the field of fungal ecology. The FESIN workshop this last summer spearheaded a push to develop an annotated reference collection of sequences to be used for identification. This proposal addresses the problem of misidentifications in GenBank, and it will be a crucial piece of infrastructure for the field. The work by Dr. Vellinga in the last year resulted in description of two new species within the genus Lepiota from California; this basic taxonomic work remains important because so many of our common fungal species are still undescribed. In addition to the academic and applied science, Dr. Vellinga, and Dr. Bruns continue to interact with the public through local mushroom clubs. This effort helps forge links between the general public and the University.
Publications
- Schecter, S.P. and T.D. Bruns 2008. Serpentine and nonserpentine ecotypes of Collinsia sparsiflora associate with distinct arbuscular mycorrhizal fungal assemblages. Mol. Ecol. 17: 3198-3210
- Peay, K. G., Kennedy, P. G., Bruns T. D. 2008 Fungal community ecology: a hybrid beast with a molecular master. BioScience 58(9): 799-810.
- Bruns, T.D., A.E. Arnold, and K.W. Hughes. 2008. Fungal networks made of humans: UNITE, FESIN, and frontiers in fungal ecology. New Phytol. 177(3): p. 586-588.
- Vellinga, E.C. & W.J. Sundberg. 2008. Lepiotaceous fungi in California, U.S.A. - 6. Lepiota castanescens. Mycotaxon 103: 97-108.
- Vellinga, E.C., 2007. Lepiotaceous fungi in California, U.S.A. - 5. Lepiota oculata and its look-alikes. Mycotaxon 102: 267-280.
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Progress 01/01/07 to 12/31/07
Outputs
OUTPUTS: Bruns and colleagues published three peer-reviewed papers and a non-reviewed meeting report last year, and postdocs Kennedy and Vellinga, and graduate students Peay and Hynson published and an additional 9 peer-reviewed papers. In addition Bruns co-founded FESIN - the Fungal Environmental Sampling and Informatics Network (http://www.bio.utk.edu/fesin/title.htm), organized and spoke at a workshop for it at the Ecological Society of America meetings, and organized and presented at a joint meeting of FESIN and UNITE (User-friendly Nordic ITS Ectomycorrhizal database) in Copenhagen. We continued to work on the Pt. Reyes Mycobiltz. This is an effort to enlist the general public to catalogue the macrofungi of Pt. Reyes National Seashore. In the last year we co-organized two forays for the Pt. Reyes mycobiltz, authored and updated the text fof the Mycoblitz websites (http://www.mykoweb.com/PtReyes/, and http://plantbio.berkeley.edu/~bruns/tour/mycoblitz1.html), and curated
herbarium collections derived from the mycoblitz. We presented scholarly talks at the Ecological Society of America, and The British Mycological Society, and gave lectures to local amateur mushroom groups (Santa Cruz Fungus Federation, and Sonoma Mycological Society).
PARTICIPANTS: Thomas D. Bruns - PI Two postdoctoral associates and five students were trained: Dr. Else Vellinga (postdoc) Dr. Peter Kennedy (Postdoc) Graduate Students: Kabir Peay, Nicole Hynson, Valerie Wong, Shannon Schechter, Nicholas Rosenstock
TARGET AUDIENCES: Ecologists, Land Managers, and members of the general public with advanced interests in fungi are the primary target audience.
Impacts
Results from the Peay et al 2007 paper are important because prior work on microbial species-area relationships showed only a very weak change in species with additional area sampled. Our work demonstrates that EM fungi are very similar to plants in terms of the species-area relationship. In addition the nested pattern that we discovered suggests that many species are poor dispersers even at the scale of a few hundred meters. Both results mean that if one wants to conserve EM fungal diversity the size of area necessary to do so will be very similar to that required for plants. This paper was on the cover of Ecological Letters and was selected by the "Faculty of 1000" as a significant paper. In the Kennedy et al 2007 paper we show that: 1) competition among the earliest EM species that colonize pine roots is highly condition dependent and that strong hierarchies or networks are not dominant factors, and 2) some EM species result in significantly greater nitrogen content
in their hosts, but these effects disappear when the fungi involved are co-inoculated with competitors. These results have a direct impact on our understanding of early stages in EM community development, and have applications to the commercial inoculation of pine seedlings. The results from the Plamboeck et al 2007 paper shows that particular species of EM fungi appeared to be more efficient at water transfer between plant hosts than others, but the type of tracer used effected the outcome. This result is important because it brings into question earlier dye-based studies of EM water transport. The work with FESIN has just begun, but we have already helped to coordinate the development of infrastructure such as the ongoing work on fungal oligonucleotide identification arrays and the curation of sequence databases. The Pt. Reyes Mycoblitz effort has now documented over 500 mycofungi at Pt. Reyes National seashore. It has become an important form of public outreach as well as a model
for other such efforts that are now expanding to the Pacific Northwest and Colorado.
Publications
- Matheny, P.B., J.M. Curtis, V. Hofstetter, M.C. Aime, J.M. Moncalvo, Z.W. Ge, Z.L. Yang, J.C. Slot, J.F. Ammirati, T.J. Baroni, N.L. Bougher, K.W. Hughes, D.J. Lodge, R.W. Kerrigan, M.T. Seidl, D.K. Aanen, M. DeNitis, G.M. Daniele, D.E. Desjardin, B.R. Kropp, L.L. Norvell, A. Parker, E.C. Vellinga, R. Vilgalys and D.S. Hibbett. 2006. Major clades of Agaricales: a multilocus phylogenetic overview. Mycologia, 98(6): p. 982-995.
- Vellinga, E.C., 2007. Lepiotaceous fungi in California, U.S.A.- 4. Type studies of Lepiota fumosifolia and L. petasiformis. Mycotaxon 98: 225-232.
- Vellinga, E.C., 2007. Lepiotaceous fungi in California, U.S.A.-3. Pink and lilac species in Leucoagaricus sect. Piloselli. Mycotaxon 98: 213-224.
- Vellinga, E.C., 2007 Lepiotaceous fungi in California, U.S.A.-2. Lepiota rhodophylla. Mycotaxon 98: 205-211.
- Vellinga, E.C. & R.M. Davis, 2007. Lepiotaceous fungi in California, U.S.A.-1. Leucoagaricus amanitoides. Mycotaxon 98: 197-204.
- Pringle, A. & E.C. Vellinga, 2006. Last chance to know? Using literature to explore the biogeography and invasion biology of the death cap mushroom Amanita phalloides (Vaill. ex Fr. :Fr.) Link. Biological Invasions 8: 1131-1144.
- Katja Zimmer, Nicole A. Hynson, Gerhard Gebauer, Edith B. Allen, Michael F. Allen and David J. Read. 2007. Wide geographical and ecological distribution of nitrogen and carbon gains from fungi in pyroloids and monotropoids (Ericaceae) and in orchids. New Phytologist 175:166-175.
- Kennedy P. G. and K. G. Peay. 2007. Different soil moisture conditions change the outcome of the ectomycorrhizal symbiosis between Rhizopogon species and Pinus muricata. Plant and Soil 291: 155-165.
- Plamboeck, A.H., T.E. Dawson, L.M. Egerton-Warburton, M. North, T.D. Bruns, and J.I. Querejeta. 2007. Water transfer via ectomycorrhizal fungal hyphae to conifer seedlings. Mycorrhiza 17: p. 439-447.
- Kennedy, P. and T. Bruns. 2007. Mycorrhizas take root at the Ecological Society of America. New Phytol. 176(4): p. 745-748
- Vellinga, N.L. Bougher, O. Ceska, P.-A. Moreau, M.A. Neves & J.F. Ammirati, 2007. Taxonomy of displaced species of Tubaria. Mycologia 99(4):569-585.
- Kennedy, P.G., S. Hortal, S.E. Bergemann, and T.D. Bruns. 2007. Competitive interactions among three ectomycorrhizal fungi and their relation to host plant performance. J Ecol. 95: p.1338-1345.
- Peay, K. G., Bruns T. D. Kennedy, P. G., Bergemann, S. E., and M. Garbelloto. 2007. A strong species-area relationship for eukaryotic soil microbes: island size maters for ectomycorrhizal fungi. Ecology Letters 10:470-480
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Progress 01/01/06 to 12/31/06
Outputs
We have published five main results in the last year. 1) We show that populations of the ectomycorrhizal fungus RHIZOPOGON that are isolated by even a few kilometers are genetically distinct. 2) We developed a real-time PCR assay for two species of RHIZOPOGON and used it to assay competition in a field setting. 3) We found that the spatial structure of resistant propagules communities of ectomycorrhizal fungi is relatively simple and homogeneous, but responds slightly differently to ABIES and PINUS seedlings; PINUS was colonized more frequently by all species and ABIES was not colonized by RHIZOPOGON. 4) We found that the most common RHIZOPOGON species do not discriminate among PINUS species, but that some PINUS species are more receptive to colonization. PINUS CONTORTA and P. MURRICATA were the most receptive host species. 5) We found that heating of soil to 75o C eliminates some ectomycorrhizal inoculum, but RHIZOPOGON OLIVACEOTINCTUS actually increased its
colonization with heat treatment. In addition we published a highly visible commentary, a layman's synopsis of the effect of the Mt. Vision fire on mycorrhizae, and the first species list of macrofungi for the Northern Channel islands.
Impacts
The first result means that most of the genetic diversity of species of an important ectomycorrhizal genus is found between populations. This is important if one is interesting in finding useful genotypes for commercial inoculation. The real-time PCR assay made it possible to show that competitive experiments run in the field yielded the same results as earlier growth chambers experiments. This means that species and isolates of RHIZOPOGON can be effectively screened for competitive abilities on seedlings in the laboratory. The relative uniformity of resistant propagules means that ectomycorrhizal inoculum is likely to be high even in post-fire and post-logging settings for PINUS, but is more limited for ABIES. The receptivity of pine to a large set of RHIZOPOGON species coupled with the abundance of RHIZOPOGON spores in pine soils means that pine species can easily establish anywhere that other pines have been grown. This is important in the context of global change
because it means that as pines migrate up elevational and latitudinal gradients their seedlings are likely to encounter compatible ectomycorrhizal inoculum. RHIZOPOGON OLIVACEOTINCTUS is listed as a species of concern in the Northwest Forest plan, but with what we have learned about its prevalence in soil, its occurrence after fire, and its response to soil heating we now think it is a fairly common post-fire species that exists between periods of disturbance as dormant spores.
Publications
- Izzo, A., Canright, M., and Bruns, T.D. 2006. The effects of heat treatments on ectomycorrhizal resistant propagules and their ability to colonize bioassay seedlings. Mycol. Res. 110:196-202
- Bruns, T.D. 2006. A Kingdom Revised. (News and Views) Nature 443: 758-759.
- Bruns, T.D., Baar, J., Grogan, P., Horton, T.R., Kretzer, A., Redecker, D., Tan, J. and Taylor, D. L. 2005. Natural History and Community Dynamics of Ectomycorrhizal Fungi following the Mt. Vision Fire. pp 33-40. In Lessens Learned from the October 1995 Mt. Vision Fire; CD ROM published by Points Reyes National Seashore.
- Grubisha LC, Trappe JM, Bruns TD. 2005. Preliminary record of ectomycorrhizal fungi on two California Channel Islands. Eds. Garcelon, DK, Schwemm, CA. In: Proceedings of the Sixth California Islands Symposium, Ventura, California, December 1-3, 2003, pp. 171-183. National Park Service Technical Publication CHIS-05-01, Institute for Wildlife Studies, Arcata, California.
- Grubisha, L.C., Bergemann, S.E., and Bruns, T.D. 2006. Host islands within the California Northern Channel Islands create fine-scale genetic structure in two sympatric Rhizopogon species. Mol. Ecol. (in press).
- Kennedy, P. G., Bergemann, S. E., Hortal S., Bruns T. D. 2006 Determining the outcome of field-based competition between two Rhizopogon species using real-time PCR Mol. Ecol. In Press.
- Izzo, A., Nguyen, D. T., Bruns T.D. 2006. Spatial structure and richness of ectomycorrhizal fungi colonizing bioassay seedlings from resistant propagules in a Sierra Nevada forest: comparisons using two hosts that exhibit different seedling establishment patterns. Mycologia 98:374-383.
- Rusca, T.A. Kennedy, P. G., and Bruns T. D. 2006. The effect of different pine hosts on the sampling of Rhizopogon spore banks in five Eastern Sierra Nevada forests. New Phytol. 170(3):551-560.
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Progress 01/01/05 to 12/31/05
Outputs
We have published four results in the last year. 1) We showed that invertebrates facilitate spore dispersal of TOMENTELLA SUBLILACINA, and that viable spores move through the soil food web 2) We located multi microsatellite loci in two species of RHIZOPOGON, designed primers for them, and showed that they are variable within and among populations. 3) We tested seeds of MONOTROPA UNIFLORA from different regions and showed that they germinate in response to multiple species in the Russulaceae, but only develop well with the species that was associated with the parent plants. 4) We showed that competition between RHIZOPOGON OCCIDENTALIS and R. SALEBROSUS is won by the species whose spores germinate first.
Impacts
The first result is significant because TOMENTELLA SUBLILACINA is a dominant species in many conifer forests, and the manner in which its spores disperse has never been clear. Dispersal via the invertebrate food web means that most spores will not move very far. The second result is important because it provides a tool for examination of the population structure of two common pine-associated mycorrhizal symbionts. The third result is significant because it helps to explain why the observed mycorrhizal specificity of adult plants is narrower than the specificity of fungal induced seed germination. This is an important piece of information because many of the epiparasitic plants involved in such interactions are rare or endangered. The forth result represents one of the first mechanistic explanations for the way in which ectomycorrhizal competitive interactions are structured. The species involved are important primary colonizers of pine seedlings.
Publications
- Lilleskov, E.A. and Bruns, T.D. 2005. Spore dispersal of a resupinate ectomycorrhizal fungus, Tomentella sublilacina, via soil food webs. Mycologia 97(4): 762-769
- Grubisha, L. C, Kretzer, A.M., and Bruns, T.D. 2005 Isolation and characterization of microsatellite loci from the truffle-like ectomycorrhizal fungi Rhizopogon occidentalis and Rhizopogon vulgaris. Mol. Ecol. Notes 5: 608-610.
- Bidartondo, M.I. and Bruns, T.D. 2005. On the origins of extreme mycorrhizal specificity in the Monotropoideae (Ericaceae): performance trade-offs during seed germination and seedling development. Mol. Ecol. 14: 1549-1560.
- Kennedy, P. G and Bruns, T. D. 2005. Priority effects determine the outcome of ectomycorrhizal competition between two Rhizopogon species colonizing Pinus muricata seedlings. New Phytol. 166(2): 631-638
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Progress 01/01/04 to 12/31/04
Outputs
We have published four main results in the last year. 1) We found that below-ground species composition of ectomycorrhizal fungal communities varies strongly within a few meters at multiple sites. In fact, within most forests the similarly of fungal species composition between points separated by more than two meters is no greater than the similarly between two points that are separated by hundreds of meters. 2) We showed that the evidence for the presence of lignin peroxidase genes in ectomycorrhizal fungi, which was previously published by others, was based on PCR artifacts, and that the conclusions concerning the loss of ectomycorrhizal habit were based on some weak assumptions, limited sampling, and are model dependent. 3) We found that CORALLORHIZA MACULATA, a non-photosynthetic orchid, is composed of host races that are specifically associated with particular lineages of ectomycorrhizal fungi within the family Russulaceae. 4) We found that a wide variety of
photosynthetic, terrestrial orchids that are found in dark woodland understories are associated with ectomycorrhizal fungi and have carbon and nitrogen isotope signatures that suggest epiparasitic lifestyles.
Impacts
The first result directly affects belowground sampling strategies, and it also puts spatial parameters on the exceptional diversity of ectomycorrhizal fungi. The second result is important because the lignin peroxidase report was widely accepted and used as further evidence for the supposed saprophytic abilities of ectomycorrhizal fungi, and the purported loss of mycorrhizal ability was similarly accepted without close examination of the basis for the claims. The third result provides a detailed example of an important emerging pattern: non-photosynthetic, "epiparasitic" plants that obtain their carbon from mycorrhizal fungi are highly specialized on closely related fungi. The fourth result shows the epiparasitic lifestyle may occur facultatively in photosynthetic orchids that live in deep shade. This provides an unexpected example of carbon-flow among dissimilar plants connected by a common mycorrhizal network
Publications
- Taylor, J.W., Spatafora, J,. O'Donnell, K.L., Lutzoni, F. James, T., Hibbett, D. S., Geiser, D., Bruns, T.D., and Blackwell. M. 2004. Fungi. In: The Tree of Life, J. Cracraft and M. Donoghue (eds.). Oxford.
- Lilleskov, E. A., Bruns, T.D., Horton, T.R., Taylor, D.L., and Grogan, P. 2004. Detection of forest stand-level spatial structure in ectomycorrhizal fungal communities. FEMS Microb. Ecol. 49(2):319-332
- Bruns, T.D. and Shefferson, R. P. 2004. Evolutionary studies of Ectomycorrhizal fungi: recent advances and future directions. Can. J. Bot. 82:1-11.
- Taylor, D.L., Bruns T.D., Hodges, S.A. 2004. Evidence for mycorrhizal races in a cheating orchid. Proc. Roy. Soc. Lond. (B): 271:35-43
- Bidartondo, M.I., Burghardt, B., Gebauer, G., Bruns, T.D. and Read, D.J. 2004. Changing partners in the dark: Isotopic and molecular evidence of ectomycorrhizal liaisons between forest orchids and trees. Proc. Roy. Soc. Lond. (B). 271:1799-1806.
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Progress 01/01/03 to 12/31/03
Outputs
Results published from this project in 2003 show: 1) When young tan oaks (LITHOCARPUS DENSIFLORA) grow under a Douglas-fir (PSEUDOTSUGA MENZIESII) canopy both trees associate with the most of same species of ectomycorrhizal fungi. All of the most abundant fungi are shared by both trees and most of the fungi that appear to be unique to one or the other host were relatively rare. 2) Even closely related sister species of the non-photosynthetic orchid HEXALECTRIS SPICATA specialize on different mycorrhizal associates. 3) The non-photosynthetic liverwort CRYPTOTHALLUS MIRABILIS associates only with particular ectomycorrhizal fungi in the genus TULASNELLA. 4) RHIZOPOGON species form abundant spore banks in pine forest soils across the state of California, and these can be sampled efficiently by soil dilution and pine seedling bioassays. 5) Competition between ectomycorrhizal fungi can be experimentally manipulated and monitored in real time, and outcomes of such
competition can be manipulated by altering soil nutrients.
Impacts
Results one, two and three show the pervasiveness and importance of common mycorrhizal networks. The first example shows that competing tree species are likely to be indirectly connected by their root symbiotic fungi; this may have a direct impact on the ability of tan oak to grow in the understory. The second and third examples show that when plants become parasitic on these networks they specialize on particular fungi within these systems. This pattern had been previously shown, but these examples are impressive because of the level of specificity that they demonstrate. The result with the non-photosynthetic liverwort is important for another reason; it showed that a group of fungi that was not previously thought to be involved in ectomycorrhizal interactions, forms such relationships with both pine and birch trees. Result four is important because RHIZOPOGON species are some of the most common mycorrhizal associates of pine following severe disturbance. This result
shows that they are essentially waiting, as spores, for such disturbance events. Result five is significant because it developed a system that enables one to examine interactions between mycorrhizal fungi under laboratory settings. Currently we know very little about such interactions even though we know that they are important in nature.
Publications
- Kennedy, P.G., Izzo, A.D. , and Bruns, T.D. 2003. High potential for common mycorrhizal networks between understory and canopy trees in a mixed evergreen forest. J. Ecology. 91: 1071-1080 .
- Taylor, D.L., Bruns, T.D., Szaro, T.M, and Hodges, S.A. 2003. Divergence in mycorrhizal specialization within Hexalectris spicata , a nonphotosynthetic desert orchid. Am. J. Bot. 90: 1168-1179.
- Bidartondo, M.I., Bruns, T.D., Wiess, M., Sergio, C., and Read, D.J. 2003. Specialized cheating of the ectomycorrhizal symbiosis by an epiparasitic liverwort. Proc. Roy. Soc. Lond. B. 270: 835-842
- Kjoller, R. and Bruns, T. D. 2003. Rhizopogon spore bank communities within and among Californian pine forests. Mycologia 95:603-613.
- Lileskov, E. A. and Bruns, T.D. 2003. Root colonization dynamics of two ectomycorrhizal fungi of contrasting life histories mediated by organic nutrient additions. New Phytol. 159:141-151
- Vellinga, E.C., de Kok, R.P.J., and Bruns, T.D. 2003. Phylogeny and taxonomy of Macrolepiota (Agricaceae) Mycologia 442-456.
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Progress 01/01/02 to 12/31/02
Outputs
The work published from this project in the last year makes the following points: 1) At least some non-photosynthetic plants can use arbuscular mycorrhizal fungi to obtain carbon from surrounding plants, and when they do so, they utilize only specific AM fungi. 2) The level of specificity of non-photosynthetic plants for their fungal hosts extends into cryptic species that are only detectable though molecular characterization, and in some cases geographic patterns exist in these interactions. 3) we hypothesize that within the broad realm of mycorrhizal symbiosis a continuum exists between mutualistic and parasitic interactions, and the most specific interactions may be those that are more parasitic in nature. In addition, work that is completed but not yet published shows that RHIZOPOGON species are abundantly present in the soil spore bank throughout California's pine forests, and that species composition varies regionally.
Impacts
Result one is very important because the view that AM fungi are not involved in the transfer of carbon between dissimilar plants remains strongly held by others in the field. Our results contradict this view and suggest that plant competitive interactions could be structured though their shared fungal symbionts. The two reviews on specificity and mycoheterotrophic plants are likely to impact the field of mycorrhizal ecology, as they are the only recent reviews written on either topic for at least ten years, and both present novel ideas not expressed in earlier work.
Publications
- Bidartondo, M. I., Redecker, D.,Hijri, I., Wiemken, A., Bruns, T.D., Dominguez, L., Sersic, A., Leake, J. R., & Read. D. J. 2002. Epiparasitic plants specialized on arbuscular mycorrhizal fungi. Nature 419;389-391.
- Bruns, T.D., Bidartondo, M.I. Taylor, D.L. 2002. Host specificity in ectomycorrhizal communities: what do the exceptions tell us? Integ. and Comp. Biol. 42:352-359.
- Bidartondo, M.I.,and Bruns, T.D. 2002. Fine-level mycorrhizal specificity in the Monotropoideae (Ericaceae): specificity for fungal species groups. Mol. Ecol. 11: 557-570.
- Bruns, T.D., Kretzer, A.M., Horton, T.R. Stendell. E. A-D, Bidartondo, M. I. and Szaro, T. M. 2002. Current investigations of fungal ectomycorrhizal communities in Sierra National Forest. pp 83-89 in Proceedings of a Symposium on the Kings River Sustainable Forest Ecosystem Project: Progress and Current Status USDA Forest Service Gen. Tech. Rep. PSW-GTR-183.
- Bruns, T. D. and Bidartondo, M.I. 2002. Molecular windows into the below ground interactions of ectomycorrhizal fungi. The Mycologist 16:47-50
- Bruns, T. D. 2001. ITS reality. Inoculum 52:2-3.
- Taylor, D.L., Bruns, T.D., Leake, J.R., Read, D.J. 2002. Mycorrhizal Specificity and Function in Myco-heterotrophic Plants. pp. 379-437. In Ian R. Sanders and Marcel van der Heijden (eds). The Ecology of Mycorrhizas. Springer-Verlag, Berlin.
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Progress 01/01/01 to 12/31/01
Outputs
The primary findings of the work published this year are: 1) Plants in the Monotropoideae all exhibit high levels of specificity for particular ectomycorrhizal fungi. Each lineage within the family has targeted different fungi, and geographically separated populations often target related but different fungi. Many of these plants are listed as rare or endangered in parts of their range, and these result show that managing for their fungal symbionts will be key to maintaining the plant populations. 2) Ectomycorrhizal fungal inoculum was found to be sparse, low in diversity, and spatially restricted to forest borders in PINUS LONGAEVA communities. These are high altitude, dry, harsh environments where establishment of new trees is exceedingly rare and restricted to currently forested areas. The limited inoculum is likely to reinforce this pattern. 3) We reviewed the impact of molecular identification methods on the field of ectomycorrhizal ecology. Much progress as been
made on describing the basic patterns of community structure and effects of various disturbances on these communities. The problems of scale coupled with the limits to sample size were identified as one of the outstanding problems in the field. Development of methods for identifying and quantifying the mycelial component is an important goal for future work.
Impacts
Mycorrhizal fungi are essential for plant growth and development, and they play pivotal roles in forest nutrient cycling and ecosystem function. This work is focused on achieving a better understanding of the basic biology and ecology of key fungal species. Such knowledge is a prerequisite for understanding how natural and human disturbances effect these systems, and ultimately for manipulating them to achieve management goals.
Publications
- Bidartondo, M.I.,and Bruns, T.D. 2001. Extreme specificity in epiparasitic Monotropoideae (Ericaceae): Widespread phylogenetic and geographic structure. Mol. Ecol. 10: 2285-2295
- Bidartondo, M.I., Barr, J., and Bruns, T.D. 2001. Low ectomycorrhizal inoculum potential and diversity from soils in and near ancient forests of bristlecone pine (Pinus longaeva). Can. J. Bot. 79:293-299
- Horton, T. R., and T.D. Bruns. 2001. The molecular revolution in ectomycorrhizal ecology: Peeking into the black-box. Mol. Ecol. 10: 1855-1871
- Lilleskov, E. A. and Bruns, T. D. 2001. Nitrogen and ectomycorrhizal fungal communities: what we know, what we need to know. New Phytol. 149:156-158
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Progress 01/01/00 to 12/31/00
Outputs
The main highlights of the work published this year are : 1) individual genotypes of several late-stage ectomycorrhizal species cover small areas of the forest floor; this means that spore establishment is an ongoing process and is more important that vegetative spread for these species. 2) Differences in post-fire ash deposition can have dramatic short-term effects on Nitrogen availability. This has measurable effects on plant community structure, but not on ectomycorrhizal community structure. The lack of a measurable effect on the fungal community is at least partially due to the high diversity and spatial variation. 3) A small set of arbuscular mycorrhizal fungi species are distantly related to all others based on SSU rRNA gene sequences. These species also exhibit polymorphic spore states and unusual hyphal staining properties that are not known from other members of the Glomales. In addition to the published work, we have isolated and sequenced the first
microsatellite loci from TOMENTELLA SUBLILACINUS. These will be used to examine its breeding biology, and the spatial extent of genetic individuals below ground. We have also discovered that spores of TOMENTELLA SUBLILACINUS are dispersed locally by soil invertebrates.
Impacts
Mycorrhizal fungi are essential for plant growth and development, and they play pivotal roles in forest nutrient cycling and ecosystem function. This work is focused on achieving a better understanding of the basic biology and ecology of key fungal species. Such knowledge is a prerequisite for understanding how natural and human disturbances effect these systems, and ultimately for manipulating them to achieve management goals.
Publications
- REDECKER, D., SZARO, T. M., BOWMAN, J. R., BRUNS, T.D. 2000. Small genets of LACTARIUS XANTHOGALACTUS, RUSSULA CREMORICOLOR and AMANITA FRANCHETI in late stage ectomycorrhizal successions. Mol. Ecol. in press
- GROGAN, P, BAAR, J. AND BRUNS, T.D. 2000. Below-ground ectomycorrhizal community structure in a recently burned bishop pine (PINUS MURICATA) forest: spatial heterogeneity predominates over potential effects of ash deposition. J Ecol. 88:1051-1062.
- GROGAN, P., BRUNS, T.D. AND CHAPIN, F.S. III. 2000. Ash effects on ecosystem nitrogen cycling in a recently burned Bishop Pine (P. muricata) forest. Oecologia 122:537-544.
- REDECKER, D. MORTON, J. B., BRUNS, T. D. 2000. Molecular phylogeney of the arbuscular mycorrhizal fungi GLOMUS SINUOSUSM and SCLEROCYSTIS COREMIOIDES. Mycologia 92: 282-285.
- REDECKER, D. MORTON, J. B., BRUNS, T. D. 2000. Ancestral lineages of Arbuscular mycorrhizal fungi (Glomales). Mol. Phyl. Evol. 14:276-284
- HUGHEY, B. D., G. C ADAMS, T. D. BRUNS, D. S. HIBBETT. 2000 Phylogeny of CALOSTOMA, The geleatinous-stalked puffball, based on nuclear and mitochondrial ribosomal DNA sequences. Mycology 92: 94-104.
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Progress 01/01/99 to 12/31/99
Outputs
The work on ectomycorrhizal spore bank community and post-fire succession shows that: 1) the soils in and around Pt. Reyes pine forests are replete with spores of RHIZOPOGON species and ectomycorrhizal ascomycetes; 2) when the forest is highly disturbed these are the taxa that colonize newly established pine seedlings; 3) these were not abundant or common associates of mature trees in the undisturbed forest. We also found that whereas SUILLUS PUNGENS is a very common post-fire associate, each mushroom is a derived from a unique genotype. This contrasts with the prefire situation where one genotype of SUILLUS PUNGENS, covered at least 350 square meters of the forest; we have yet to find any evidence that this genotype, or any other that existed in the pre-fire forest, survived the fire. In contrast, we found that in a less severe fire, in which the mature trees survived, the ectomycorrhizal biomass is substantially reduced, but fungi resident on deeper roots survived.
Over the past year we have mapped the occurrence of RUSSULA, LACTARIUS and TOMENTELLA species in multiple sites. Our preliminary evidence for RUSSULA and LACTARIUS suggest that individual genotypes are very small; from this we infer that spores are much more important than vegetative growth in contributing to the spatial patterns observed in these species. This was an unexpected result because much previous evidence suggested that species that dominated mature forest settings do so primarily by vegetative growth.
Impacts
(N/A)
Publications
- TAYLOR, D.L. BRUNS, T. D., 1999. Community structure of ectomycorrhizal fungi in a PINUS MURICATA forest: minimal overlap between mature forest and resistant propagule community. Mol. Ecol. 8:1837-1850.
- BAAR, J., HORTON, T. R., KRETZER, A., BRUNS, T. D. 1999. Mycorrhizal recolonization of PINUS MURICATA from resistant propagules after a stand-replacing wildfire. New Phytol. 143:409-418
- STENDEL, E. C., T. R. HORTON, T. D. BRUNS. 1999 Short-term effects of a ground fire on the ectomycorrhizal community. Mycol. Res. Mycol. Res. 103:1353-1359
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Progress 01/01/98 to 12/31/98
Outputs
We have sampled seedlings at two additional sites in the Pt. Reyes Fire study. The basic pattern reported last year is reinforced by these new data. The dominant fungi on the seedlings continue to be members of the Suilloideae, primarily RHIZOPOGON and ALPOVA, and members of the Ascomycota, particularly TUBER and WILCOXINA. However, members of the Russulaceae that were dominant before the fire are also present. We have begun to use Amplified Fragment Length Polymorphisms in conjunction with mapping of fruitbodies to characterize the size of individual fungal mycelia. For AMANITA FRANCHETI, and LACTARIUS XANTHOGALACTUS we have found that individual mycelia are relatively small and the number of different individuals is high. This contrasts with the situation we found in SUILLUS PUNGENS, where at least some individuals were very large. These results suggest that even in the mature forests AMANITA and LACTARIUS continue to establish frequently by spore, while SUILLUS may
expand primarily by vegetative spread. We have investigated evolutionary relationships in Glomalean fungi and found four species that represent unexpectedly divergent lineages. The 18S rRNA genes of these species are different enough from all other members of the order that the standard Glomalean-specific primers do not detect them. We have designed new primers to correct this problem.
Impacts
(N/A)
Publications
- BRUNS, T.D., SZARO, T. M., GARDES, M., CULLINGS, K. W., PAN, J. J., TAYLOR, D.L., HORTON, T. R., KRETZER, A., GARBELOTTO, M. and LI. Y. 1998. A sequence database for the identification of ectomycorrhizal basidiomycetes by phylogenetic analysis. Mol. Ecol. 7:257-272.
- HORTON, T. R. AND BRUNS, T. D. 1998. Multiple-host fungi are the most frequent and abundant ectomycorrhizal types in a mixed stand of Douglas-Fir (PSEUDOTSUGAMENZIESII D. Don) and bishop pine (PINUS MURICATA D. Don). New Phytol. 139:331-339
- BONELLO, P., BRUNS, T. D. AND GARDES, M. 1998. Genetic structure of a natural population of the ectomycorrhizal fungus SUILLUS PUNGENS. New Phytol. 138:533-542.
- HORTON, T. R., CAZARES, E., AND BRUNS, T. D. 1998. Ectomycorrhizal, vesicular arbuscular and dark-septate fungal colonization of Bishop pine (PINUS MURICATA) seedlings in the first five months of growth after fire. Mycorrhiza 8: 11-18
- BRUNS, T. D., BONELLO, P, and SZARO, T. M. 1998. Genets of AMANITA FRANCHETI are relatively small in a thirty five year old pine forest. Inoculum 48:12 or gopher://nmnhgoph.si.edu:70/00/.docs/inoculum_data/abstrac4
- REDECKER, D., MORTON, J. B., BRUNS, T. D. 1998. An ancestral lineage of arbuscular mycorrhizal fungi produces spores both of ACAULOSPORA and GLOMUS type. Second International Conference on Mycorrhizae, Programme and Abstracts. July 5-10, 1998. Uppsala, Sweden. p.143 or http://www.icom2.slu.se/ABSTRACTS/Redecker.html
- HORTON, T.R., BRUNS, T. D., PARKER, V. T., and MOLINA, R. 1998. Patterns of fungal community structure as a function of ectomycorrhizal root biomass: data from four plant communities. Second International Conference on Mycorrhizae, Programme and Abstracts. July 5-10, 1998. Uppsala, Sweden. p.84 or http://www.icom2.slu.se/ABSTRACTS/Horton.html
- BRUNS, T. D., SZARO, T. M., GARDES, M., CULLINGS, K., PAN, J., TAYLOR, D. L., THOMAS H., KRETZER, A., GARBELOTTO, M., and LI, Y. 1998. Identification of unknown ectomycorrhizal fungi to family and subfamily level by sequence analyses. Second International Conference on Mycorrhizae, Programme and Abstracts. July 5-10, 1998. Uppsala, Sweden. p.35 or http://www.icom2.slu.se/ABSTRACTS/Bruns.html
- BAAR, J., VALINLUCK, V. and BRUNS, T. D. 1998. Fire-induced changes of the mycorrhizal flora of PINUS MURICATA. Second International Conference on Mycorrhizae, Programme and Abstracts. July 5-10, 1998. Uppsala, Sweden. p.29 or http://www.icom2.slu.se/ABSTRACTS/Baar.html
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Progress 01/01/98 to 12/01/98
Outputs
We have sampled seedlings at two additional sites in the Pt. Reyes Fire study. The basic pattern reported last year is reinforced by these new data. The dominant fungi on the seedlings continue to be members of the Suilloideae, primarily RHIZOPOGON and ALPOVA, and members of the Ascomycota, particularly TUBER and WILCOXINA. However, members of the Russulaceae that were dominant before the fire are also present. We have begun to use Amplified Fragment length Polymorphisms in conjunction with mapping of fruitbodies to characterize the size of individual fungal mycelia. For AMANITA FRANCHETI, and LACTARIUS XANTHOGALACTUS we have found that individual mycelia are relatively small and the number of different individuals is high. This contrasts with the situation we found in SUILLUS PUNGENS, where at least some individuals were very large. These results suggest that even in the mature forests AMANITA and LACTARIUS continue to establish frequently by spore, while SUILLUS may
expand primarily by vegetative spread. We have investigated evolutionary relationships in Glomalean fungi and found four species that represent unexpectedly divergent lineages. The 18S rRNA genes of these species are different enough from all other members of the order that the standard Glomalean-specific primers do not detect them. We have designed new primers to correct this problem.
Impacts
(N/A)
Publications
- BRUNS, T. D., BONELLO, P, and SZARO, T. M. 1998. Genets of AMANITA FRANCHETI are relatively small in a thirty five year old pine forest. Inoculum 48:12 or
- REDECKER, D., MORTON, J. B., BRUNS, T. D. 1998. An ancestral lineage of arbuscular mycorrhizal fungi produces spores both of ACAULOSPORA and GLOMUS type. Second International Conference on Mycorrhizae, Programme and Abstracts. July 5-10,.
- HORTON, T.R., BRUNS, T. D., PARKER, V. T., and MOLINA, R. 1998. Patterns of fungal community structure as a function of ectomycorrhizal root biomass: data from four plant communities. Second International Conference on Mycorrhizae, Program.
- BRUNS, T.D., SZARO, T. M., GARDES, M., CULLINGS, K. W., PAN, J. J., TAYLOR, D.L., HORTON, T. R., KRETZER, A., GARBELOTTO, M. and LI. Y. 1998. A sequence database for the identification of ectomycorrhizal basidiomycetes by phylogenetic anal.
- HORTON, T. R. and BRUNS, T. D. 1998. Multiple-host fungi are the most frequent and abundant ectomycorrhizal types in a mixed stand of Douglas-Fir (PSEUDOTSUGAMENZIESII D. Don) and bishop pine (PINUS MURICATA D. Don). New Phytol. 139:331-.
- BONELLO, P., BRUNS, T. D. and GARDES, M. 1998. Genetic structure of a natural population of the ectomycorrhizal fungus SUILLUS PUNGENS. New Phytol. 138:533-542.
- HORTON, T. R., CAZARES, E., and BRUNS, T. D. 1998. Ectomycorrhizal, vesicular arbuscular and dark-septate fungal colonization of Bishop pine (PINUS MURICATA) seedlings in the first five months of growth
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Progress 01/01/97 to 12/01/97
Outputs
Our work on post-fire recovery of ectomycorrhizal fungi has shown that "late-stage" fungi such as CHROOGOMPHUS VINICOLOR, BOLETUS CHRYSENTERON, AMANITA GEMMATA, and A. MUSCARIA all fruited with seedlings as the sole host in the second year after the Pt. Reyes fire. From our prefire plots, we know that CHROOGOMPUS VINICOLOR fruited in exactly the same place as it did before the fire. This observation suggests survival of either mycelium or spores. Other species that have fruited post fire include COLTRICIA PERENNIS, AND HEBELOMA CRUSTULINIFORME. Unlike the others, these two species were not present before the fire and are therefore likely to be recent colonizers that dispersed via wind-borne spores. The dominant fungi on the roots of the seedlings are ascomycetes such as TUBER, WILCOXINA, AND TRICHARINA spp., and false truffles such as RHIZOPOGON and ALPOVA spp. From previous bioassays we know that these species had spore inoculum resident in the soil prior to the
fire. The fire, however, seems to have dramatically increased the successful colonization for several of these species. This result suggests that they are stimulated by fire in some way. Collectively, these results show that there are several different sources of post-fire ectomycorrhizal inoculum.
Impacts
(N/A)
Publications
- KRETZER, A. and BRUNS, T.D. 1997. Molecular revisitation of the genus GASTROSULLIUS. Mycologia 84:586-589.
- BAAR, J., BIDARTONDO, M.I., HORTON, T.R., LEVIN, A. and BRUNS, T.D. 1997. Post-fire recolonization of mycorrhizal fungi of PINUS MURICATA. Abstract. Inoculum 48(3):2.
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Progress 01/01/96 to 12/30/96
Outputs
This year most of our work was focused on post-fire recovery of ectomycorrhizal fungi. There are three major findings from this work. 1) Most fungi appear to survive catastrophic fire and directly recolonize the new tree seedlings. This includes so called late-stage fungi such as RUSSULA and AMANITA spp. 2) In highly disturbed soils, recolonization is by spores present in the soil spore-bank, and RHIZOPOGON spp. are the most dominant fungi in these settings. 3) Members of the genus TOMENTELLA, which were among the dominant species prior to the fire, do not appear to be common on the post fire seedlings.
Impacts
(N/A)
Publications
- TAYLOR, D.L. and BRUNS, T.D. Independent, specialized invasions of ectomycorrhizal mutualism by two non-photosynthetic orchids. Proc. Nat. Acad. Sc. (USA), IN PRESS.
- CULLINGS, K. W., SZARO, T.M. and BRUNS, T.D. 1996. Evolution of extreme specialization within a lineage of ectomycorrhizal epiparasites. Nature 379:63-66.
- KRETZER, A., LI, Y., SZARO, T. and BRUNS, T. D. 1996. Internal transcribed spacer sequences from 38 recognized species of SUILLUS SENSU LATO: Phylogenetic and taxonomic implications. Mycologia
- GARDES, M. and BRUNS, T.D. 1996. Community structure of ectomycorrhizal fungi in a PINUS MURICATA forest: above and below ground views. Can. J. Bot. 74:1572-1583.
- HORTON, T. R., BRUNS, T. D. and CHAPELA, I. 1996. Ectomycorrhizal community structure in andean Monterey pine plantations, Ecuador. Abstract p. 63 First International Conference on Mycorrhizae, Univ.
- TAYLOR, D.L. and BRUNS, T. D. 1996. Myco-heterotrophy in North American orchids: specificity and trophic links. Abstract p. 117. First International Conference on Mycorrhizae, Univ. Cal. Berkeley.
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Progress 01/01/95 to 12/30/95
Outputs
This project is focused on the ecology of ectomycorrhizal fungi. These are root symbionts that are necessary for the survival and growth of all pinaceous conifers. Our major results this year are: 1) We have compared ectomycorrhizal community structure at different locations and found that, although diversity is always very high, a small number of species account for the overwhelming majority of biomass. At all sites the dominant fungi belong to only two families: the Russulaceae and the Thelephoraceae, and the fungi involved are generalists, that is they associate with many different species of trees. This is an important finding because no consistent patterns in ectomycorrhizal communities have previously been identified. 2) We have found that epiparasitic orchids parasitize specific groups of fungi from these same two families. This provides further evidence that parasitism within the mycorrhizal relationship is usually accompanied by host specialization. 3) We
have also completed a molecular phylogeny of the genus Suillus and submitted the manuscript on it for publication. The sequence data from this study will facilitate identification of unknown mycorrhizae in this important genus of host-specialized fungi. One paper and four abstracts resulted from this work. Two additional papers are in press.
Impacts
(N/A)
Publications
- BRUNS, T. D. 1994. Thoughts on the processes that maintain local species diversity of ectomycorrhizal fungi. Pl. Soil 170:63-73.
- BRUNS, T. D., GARDES, M., HORTON, T. H., and TAYLOR, L. 1995. Ectomycorrhizal community associated with bishop pine. (Abstract) Inoculum 46(3): 6.
- HORTON, T. R. and BRUNS, T. D. 1995. Ectomycorrhizal fungi simultaneously associate with two plant species in mixed stands. (Abstract) Inoculum 46(3):19.
- KRETZER, A., LI, Y. and BRUNS, T. D. 1995. Phylogeny of Suillus as inferred fromITS sequence data. (Abstract) Inoculum 46(3): 24.
- TAYLOR, L. and BRUNS, T. D. 1995. Ectomycorrhizal epiparasitism and high specificity in the mycorrhizal associations of the phantom orchid. (Abstract) Inoculum 46(3): 41.
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Progress 01/01/94 to 12/30/94
Outputs
This project is focused on the study of the ecology of ectomycorrhizal fungi. These are root symbionts that are necessary for the survival and growth of all pinaceous conifers. Since the renewal of this project we have several significant results to report; space limitation allows us to report two of them. First, we have finally identified the second most common fungal symbiont in our sites as a TOMENTELLA species. For the last four years we knew this species only from its vegetative state and from nucleotide sequence. This year we found its fruitbody and used DNA methods (ITS-RFLPS) to match it to its vegetative state. This is an important result because we have found this species to be extremely common throughout California conifer forests and it appears to be the major colonizer of seedlings in mature coastal pine forests. It is also important because the mycorrhizal status of TOMENTELLA has only recently been demonstrated, previously it was assumed to be a wood
decaying fungus. Second, we have found good evidence for mycorrhizal sharing between Douglas-fir and Manzanita, and Douglas-fir and Bishop Pine. This result confirms what others have suspected for several years: root systems of unlike plants are connected by their fungal symbionts. However, our result is the first really good evidence from field observation based on direct identification of the mycorrhizae. One paper and three abstracts were completed in this period.
Impacts
(N/A)
Publications
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Progress 01/01/93 to 12/30/93
Outputs
Our efforts over the last two and a half years have been directed toward developing molecular methods for species-level identification of ectomycorrhizal fungi and then using these methods to investigate the basic ecology of these fungi in coastal conifer forests. Two papers derived from this work were published this year, and another is in press. The published papers present two molecular-based methods for the identification of ectomycorrhizal fungi. The paper that is in press discusses the problems presented by high fungal diversity in natural forest ecosystems and outlines the way in which emerging molecular approaches will allow us to investigate the ecological function of this diversity. One set of plot studies has now been completed. Results from this study demonstrate that the most commonly used traditional method for assaying the biodiversity of ectomycorrhizal fungi is a very bad indicator of the species abundance and importance. These results and others were
reported at the North American Conference on Mycorrhizae. Four additional plot-based studies were initiated this year in coastal Bishop pine and Douglas-fir forests; these address functional differences between various species and will assay clonal sizes of selected species. The first results from the new plots are anticipated within the next year.
Impacts
(N/A)
Publications
- CULLINGS, K., SZARO, T.M., and BRUNS, T.D. 1993. Co-evolution of the monotropoidae and their mycorrhizal associates - a test of Farenholz's rule. ABSTRACTS OF THE NORTH AMERICAN CONFERENCE ON MYCORRHIZAE, University of Guelph, Ontario,.
- BRUNS, T.D. (in press) Thoughts on the processes that maintain local species diversity of ectomycorrhizal fungi. PL. SOIL.
- BRUNS, T.D., GARDES, M. 1993. Molecular tools for the identification of ectomycorrhizal fungi: taxon-specific oligonucleotide probes for the suilloid fungi. MOLECULAR ECOLOGY 2:233-242.
- GARDES, M. and BRUNS, T.D. 1993. ITS primers with enhanced specificity of basidiomycetes: application to the identification of mycorrhizae and rusts. MOLECULAR ECOLOGY 2:113-118.
- GARDES, M., and BRUNS, T.D. 1993. The mycorrhizal guild structure of a bishop pine forest in California. ABSTRACTS OF THE NORTH AMERICAN CONFERENCE ON MYCORRHIZAE, University of Guelph, Ontario, Canada, p. 105.
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Progress 01/01/92 to 12/30/92
Outputs
Ectomycorrhizal fungi are essential root symbionts in all pinaceous forest ecosystems. Knowledge of the basic ecology of the these fungi has been difficult to obtain because of the inability to identify most species when they are associated with tree roots. Our continuing efforts have been focused on developing molecular methods for the identification of mycorrhizal fungi, and applying these methods to investigate the basic ecology of these fungi in natural forest ecosystems. Work in my lab during the last year has resulted in three publications related to molecular identification of mycorrhizal fungi or hosts from root fragments, and two publications related to evolution of these fungi and their hosts. The evolutionary papers are important for two reasons. First, the nucleotide sequences on which they are based provided the necessary knowledge for the molecular identification methods, and second they will eventually provide us with a broad prospective on the pattern
of host-symbiont interactions over evolutionary time. We also have reported the ongoing ecological work at two national meetings (see abstracts). This latter work will probably be submitted for publication within the current year.
Impacts
(N/A)
Publications
- GARDES, M. and BRUNS, T. D. 1992. Molecular sampling of mycorrhizae: opposing views from above and below ground. Inoculum Newsletter of the Mycological Society of America 43:32.
- GARDES, M. and BRUNS, T. D. 1992. Mycorrhizal guild structure: opposing views from above and below ground. Bulletin of the Ecological Society 73(2):143. BRUNS, T. D., VILGALYS, R., BARNS, S. M., GONZALES, D., HIBBETT, D. S., LANE, D. J., SIMON, L., STICKEL, S., SZARO, T. M., WEISBURG, W. G. and SOGIN, M. L. Evolutionary relationships within the Fungi: analyses of nuclear small subunit rRNA.
- CULLINGS, K. W. 1992. Design and testing of a Plant-specific PCR primer for ecological and evolutionary studies. Mol. Ecol. 1(4):233-240.
- SIMON, L., LALONDE, M., and BRUNS, T. D. 1992. Specific amplification of 18S fungal ribosomal genes from vesicular-arbuscular endomycorrhizal (VAM) roots. Appl. Envir. Microb. 58:291-295.
- CULLINGS, K. W. and BRUNS, T. D. 1992. Phylogenetic origins of the Monotropoideae inferred from partial 28S rRNA gene sequences. Can. J. Bot. 70:1703-1708.
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Progress 01/01/91 to 12/30/91
Outputs
In the last year we have refined molecular methods to identify mycorrhizal fungiand used these methods to identify associates of Bishop pine in natural stands. The important findings of the work are: 1) Several of the mycorrhizal fungi that fruit abundantly in the stand are only minor components of the mycorrhizal community. 2) Several of the major components of the mycorrhizal community are completely absent or poorly represented by fruiting. These findings are significant because most prior studies of the mycorrhizal ecology have been based on the assumption that the fruiting record of mycorrhizal fungi is a good indicator of the below ground community structure; our results suggest that this is a poor assumption.
Impacts
(N/A)
Publications
- GARDES, M., WHITE, T.J., FORTIN, J.A., BRUNS, T.D. and TAYLOR, J.W. 1991. Identification of indigenous and introduced symbiotic fungi in ectomycorrhizae by amplification of the nuclear and mitochondrial ribosomal DNA. Can. J. Bot.
- GARDES, M. and BRUNS, T.D. 1991. Rapid characterization of ectomychorrhizae using RFLP patterns of their PCR amplified-ITS. Mycol. Soc. Amer. Newsl. 42:14. (abstr.).
- BRUNS, T.D., CULLINGS, K.W. and SZARO, T.M. 1991. Pine drops, PTEROSPORA ANDROMEDIA, is specifically associated with RHIZOPOGON or a closely related taxon over a broad geographic range. Mycol. Soc. Amer. Newsl. 42:8. (abstr.).
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Progress 01/01/90 to 12/30/90
Outputs
We have developed rapid molecular methods that enable us to identify root symbiotic (mycorrhizal) fungi. We are using these methods to test two fundamental assumptions: 1) fruiting structures of these fungi provide a good measure of below ground fungal diversity and dominance, and 2) fungi observed to fruit only in the presence of a specific host are associated exclusively with that host. Our preliminary results demonstrate that at least the second assumption is occasionally false, and that mycorrhizal dominance appears to be very poorly correlated with mushroom production. These results have now been reported in two talks at the Mycological Society Meetings in San Antonio and in one talk at the American Phytopathological Society meeting in St. Louis. The first manuscripts on this work will probably be completed in the next year.
Impacts
(N/A)
Publications
- No publications reported this period.
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