MACROMYCETES PARKU W MAŁKOCINIE (NW POLSKA)

Arbuscular mycorrhizal fungi (AMF) have the potential to increase crop productivity and play a key role in the functioning and sustainability of most agroecosystems. However, limited information is available on the divervisity of AMF associated with upland rice varieties in Southwest Nigeria. Field survey was conducted to investigate colonization and diversity of AMF in 13 upland rice varieties commonly grown in Southwest Nigeria. Root and soil samples were collected from rice fields in 2012. The results showed natural root colonization of all the rice varieties by AMF with highest root colonization in ITA 157and Ofada. The spore densities retrieved from the different rhizospheres were relatively high, varying from 13 spores in UORW 111 to 174 spores in Ofada with a mean of 67.6 spores per 20 g dry soil. Glomus was observed to be the most abundant AMF genus. Funneliformis mosseae was the most frequently occurring AMF species (96.2%) with relative density (RD) of 32.2%, followed by Glomus intraradices, Claroideoglomus etunicatum, and Glomus clareium. This study showed that AMF naturally colonized the roots of these rice varieties and diversity of different AMF genera in rice rhizosphere. This study will help draw attention to natural colonization of AMF in rice producing areas of Nigeria that can influence future possibility of using inocula of the dominant AMF species in upland rice cultivation.

Understanding ecosystem carbon (C) and nitrogen (N) cycling under global change requires experiments maintaining natural interactions among soil structure, soil communities, nutrient availability, and plant growth. In model Douglas‐fir ecosystems maintained for five growing seasons, elevated temperature and carbon dioxide (CO2) increased photosynthesis and increased C storage belowground but not aboveground. We hypothesized that interactions between N cycling and C fluxes through two main groups of microbes, mycorrhizal fungi (symbiotic with plants) and saprotrophic fungi (free‐living), mediated ecosystem C storage. To quantify proportions of mycorrhizal and saprotrophic fungi, we measured stable isotopes in fungivorous microarthropods that efficiently censused the fungal community. Fungivorous microarthropods consumed on average 35% mycorrhizal fungi and 65% saprotrophic fungi. Elevated temperature decreased C flux through mycorrhizal fungi by 7%, whereas elevated CO2 increased it by 4%. The dietary proportion of mycorrhizal fungi correlated across treatments with total plant biomass (n= 4, r2= 0.96, P= 0.021), but not with root biomass. This suggests that belowground allocation increased with increasing plant biomass, but that mycorrhizal fungi were stronger sinks for recent photosynthate than roots. Low N content of needles (0.8–1.1%) and A horizon soil (0.11%) coupled with high C : N ratios of A horizon soil (25–26) and litter (36–48) indicated severe N limitation. Elevated temperature treatments increased the saprotrophic decomposition of litter and lowered litter C : N ratios. Because of low N availability of this litter, its decomposition presumably increased N immobilization belowground, thereby restricting soil N availability for both mycorrhizal fungi and plant growth. Although increased photosynthesis with elevated CO2 increased allocation of C to ectomycorrhizal fungi, it did not benefit plant N status. Most N for plants and soil storage was derived from litter decomposition. N sequestration by mycorrhizal fungi and limited N release during litter decomposition by saprotrophic fungi restricted N supply to plants, thereby constraining plant growth response to the different treatments.

The macrofungal Basidiomycete community of a Pinus sylvestris forest was investigated in 50 plots, 2 × 2 m, to see how vegetation composition and space influenced the distribution of saprotrophic and ectomycorrhizal fungi. Mantel tests and partial Mantel tests revealed a relationship between total cover of the field layer and mycorrhizal fungi, and total cover of the bottom layer and saprotrophic fungi. These results are consistent with the predictions that mycorrhizal fungi are mainly influenced by plant species present in the root zone, whereas saprotrophic fungi are mainly influenced by the plant species of the bottom layer. Variation in the abundance of tree species did not influence the distribution of macrofungal species at this scale. The spatial patterns of fungal distribution found in this study did not deviate significantly from a random distribution. Indirect ordination showed that the ectomycorrhizal fungi mainly responded to a gradient in cover of the field layer, whereas the saprotrophs seemed to respond to a complex gradient of cover of field and bottom layer, moisture, and paludification. A direct ordination using both vegetation and fungi descriptors indicated that some of the covariation in the saprotrophic fungi and the bottom layer might be coordinated responses to changes in the field layer. A considerably higher β diversity was found among the fungi than in the vegetation. Key words: basidiomycetes, saprotrophic fungi, mycorrhizal fungi, fungi–vegetation relationships, Mantel test, ordination.

A comparison of mycorrhizal and saprotrophic fungus tolerance to creosote in vitro

The successful use of natural abundances of carbon (C) and nitrogen (N) isotopes in the study of ecosystem dynamics suggests that isotopic measurements could yield new insights into the role of fungi in nitrogen and carbon cycling. Sporocarps of mycorrhizal and saprotrophic fungi, vegetation, and soils were collected in young, deciduous-dominated sites and older, coniferous-dominated sites along a successional sequence at Glacier Bay National Park, Alaska. Mycorrhizal fungi had consistently higher δ15N and lower δ13C values than saprotrophic fungi. Foliar δ13C values were always isotopically depleted relative to both fungal types. Foliar δ15N values were usually, but not always, more depleted than those in saprotrophic fungi, and were consistently more depleted than in mycorrhizal fungi. We hypothesize that an apparent isotopic fractionation by mycorrhizal fungi during the transfer of nitrogen to plants may be attributed to enzymatic reactions within the fungi producing isotopically depleted amino acids, which are subsequently passed on to plant symbionts. An increasing difference between soil mineral nitrogen δ15N and foliar δ15N in later succession might therefore be a consequence of greater reliance on mycorrhizal symbionts for nitrogen supply under nitrogen-limited conditions. Carbon signatures of mycorrhizal fungi may be more enriched than those of foliage because the fungi use isotopically enriched photosynthate such as simple sugars, in contrast to the mixture of compounds present in leaves. In addition, some 13C fractionation may occur during transport processes from leaves to roots, and during fungal chitin biosynthesis. Stable isotopes have the potential to help clarify the role of fungi in ecosystem processes.

The functioning of the plant-mycorrhiza system depends on interactions with other organisms, including saprotrophic (ST) soil fungi. The interactions between mycorrhizal and ST fungi are likely affected by fungivorous soil animals, such as Collembola. In a two-factorial laboratory experiment lasting for 30 weeks we assessed the effects of an arbuscular mycorrhizal fungus (Glomus mosseae) and Collembola (Protaphorura fimata, Heteromurus nitidus and Folsomia candida) on the community composition of ST microfungi in soil planted with the invasive grass Cynodon dactylon. The presence of mycorrhiza substantially reduced total plant biomass and reduced N and P availability to the soil microflora, though these effects were less pronounced in the presence of Collembola. The density of Collembola was high (corresponding to about 2x10(5) individuals m-2) and was not affected by the presence of G. mosseae. In spite of the large amount of mycorrhizal mycelium in soil, it contributed little to Collembola nutrition. The presence of mycorrhiza strongly affected the community structure of ST soil fungi. In particular, mycorrhiza reduced the relative abundance of Trichoderma harzianum and Exophiala sp., but increased the abundance of Ramichloridium schulzeri and several sterile forms. However, the difference between fungal communities in mycorrhizal and non-mycorrhizal treatments was much more pronounced in the presence of Collembola. Presumably, the intense grazing by Collembola destabilized the ST fungal community, thereby making it more susceptible to the influence of G. mosseae. These results document for the first time that fungal feeding soil invertebrates can significantly affect the interactions between mycorrhizal fungi and ST soil microorganisms.

●Fine roots and mycorrhizal fungi may either stimulate leaf litter decomposition by providing free-living decomposers with root-derived carbon, or may slow decomposition through nutrient competition between mycorrhizal and saprotrophic fungi. ●We reduced the presence of fine roots and their associated mycorrhizal fungi in a northern hardwood forest in New Hampshire, USA by soil trenching. Plots spanned a mycorrhizal gradient from 96% arbuscular mycorrhizal (AM) associations to 100% ectomycorrhizal (ECM)-associated tree basal area. We incubated four species of leaf litter within these plots in areas with reduced access to roots and mycorrhizal fungi and in adjacent areas with intact roots and mycorrhizal fungi. ●Over a period of 608d, we found that litter decayed more rapidly in the presence of fine roots and mycorrhizal hyphae regardless of the dominant tree mycorrhizal association. Root and mycorrhizal exclusion reduced the activity of acid phosphatase on decomposing litter. ●Our results indicate that both AM- and ECM-associated fine roots stimulate litter decomposition in this system. These findings suggest that the effect of fine roots and mycorrhizal fungi on litter decay in a particular ecosystem likely depends on whether interactions between mycorrhizal roots and saprotrophic fungi are antagonistic or facilitative.

Mycorrhizal and saprotrophic macromycetes contribute strongly to the carbon and nitrogen cycles of forest ecosystems, often studied by tracing stable isotope composition of carbon and nitrogen. The phenomenon of the saprotrophic-mycorrhizal divide highlights the difference in the stable isotope composition of fruiting bodies of mycorrhizal and saprotrophic fungi. Much less is known about the isotopic composition of the mycelium, which plays an important role in the formation of the soil organic matter and fuels the fungal trophic channel in soil food webs. In this study, we assessed whether the saprotrophic-mycorrhizal divide in the natural δ13С and δ15N values can be traced throughout entire fungal organisms. This hypothesis was tested using 16 species of ectomycorrhizal and six species of saprotrophic basidiomycetous fungi. We showed that not only fruiting bodies, but also the mycelium of ectomycorrhizal and saprotrophic fungi differs in the δ13C and δ15N values. In both ectomycorrhizal and saprotrophic fungi, the δ13C and δ15N values increased from mycelium to hymenophores and correlated positively with the total N content in the corresponding tissues. The differences between ectomycorrhizal and saprotrophic mycelium can be used to reconstruct the fungal-driven belowground carbon and nitrogen allocation, and the contribution of saprotrophic and mycorrhizal fungi to soil food webs.

Turkey oak (Quercus cerris) is one of the most important tree species in park forests and parks in Serbia. Despite this, there has been no available information in domestic literature about the parasitic fungi that affect Turkey oak in urban areas. Research carried out between 2016 and 2023 identified 19 taxa of parasitic and saprotrophic fungi that colonize Turkey oak in urban conditions: one on the roots, two on the leaves, two on the bark, seven on the trunk, two on the branches, two on the fruits, two on the stumps, and one on both leaves and fruits. The most significant fungi found were Fomes fomentarius, Inonotus nidus-pici, and Fuscoporia torulosa, which cause heart rot and are typically found on individual trees. Most of the fungi identified occurred in succession. Following primary damage, the most frequently occurring fungus was Stereum hirsutum, while after mechanical injuries, Schizophullym commune was most frequently recorded. Alternaria spp. was found on old leaves and heavily damaged leaves. To protect the urban Turkey oak trees, measures should be focused on reducing tree density and preventing mechanical injuries. The findings from this research also contribute to understanding the ecological characteristics of these fungal taxa based on their frequent occurrence in urban conditions.

Impact of Rain Forest Transformation on Roots and Functional Diversity of Root-Associated Fungal Communities

Sequencing the Fungal Tree of Life F. Martin 1 , D. Cullen 2 , D. Hibbett 3 , A. Pisabarro 4 , J. W. Spatafora 5 , S. E. Baker 6,7, I. V. Grigoriev 7 UMR INRA/UHP 1136, Interactions Arbres/Micro-Organismes, INRA-Nancy, 54280 Champenoux, France University of Wisconsin-Madison, Madison, WI, USA Clark University, Worcester, MA, USA Department of Agrarian Production, Public University of Navarre, 31006 Pamplona, Spain Dept. Botany and Plant Pathology, Oregon State University, Corvallis, OR 97331 Chemical and Biological Process Development Group, Pacific Northwest National Laboratory, Richland, Washington, USA, 99352 US DOE Joint Genome Institute, Walnut Creek, California, USA March 2011 The work conducted by the U.S. Department of Energy Joint Genome Institute is supported by the Office of Science of the U.S. Department of Energy under Contract No. DE-AC02- 05CH11231 DISCLAIMER This document was prepared as an account of work sponsored by the United States Government. While this document is believed to contain correct information, neither the United States Government nor any agency thereof, nor The Regents of the University of California, nor any of their employees, makes any warranty, express or implied, or assumes any legal responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by its trade name, trademark, manufacturer, or otherwise, does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof, or The Regents of the University of California. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof or The Regents of the University of California.

Physiological changes in host plants in response to the broad spectrum of fungal modes of infection are still not well understood. The current study was conducted to better understand the infection of in vitro cultures of Pinus sylvestris L. seedlings by three trophically diverse fungal species, Fusarium oxysporum E. F. Sm. & Swingle, Trichoderma harzianum Rifai and Hebeloma crustuliniforme (Bull.) Quél. Biochemical methods and microscopy were utilized to determine (i) which factors (apoplastic and cellular pH, reactive oxygen species, glutathione and cell death) play a role in the establishment of pathogenic, saprotrophic and mycorrhizal fungi, and (ii) whether cell death is a common response of conifer seedling tissues when they are exposed to trophically diverse fungi. Establishment of the pathogen, F. oxysporum, was observed more frequently in the meristematic region of root tips than in the elongation zone, which was in contrast to T. harzianum and H. crustuliniforme. Ectomycorrhizal (ECM) hyphae, however, were occasionally observed in the studied root zone and caused small changes in the studied factors. Colonization of the meristematic zone occurred due to host cell death. Independently of the zone, changes in cellular pH resulting in an acidic cytoplasm conditioned the establishment of F. oxysporum. Additionally, cell death was negatively correlated with hydrogen peroxide (H2O2) in roots challenged by a pathogenic fungus. Cell death was the only factor uniquely associated with the colonization of host roots by a saprotrophic fungus. The mechanism may differ, however, between the zones since apoplastic pH was negatively correlated with cell death in the elongation zone, whereas in the meristematic zone, none of the studied factors explained cell death. Colonization by the ECM fungus, H. crustuliniforme, was associated with a decreasing number of cells with acidic apoplast and by production of H2O2 in the elongation zone resulting in cell death. Saprotrophic and ECM fungi had a greater effect on cell acidification in the meristematic zone than the pathogenic fungus.

The sapro-rhizosphere: Carbon flow from saprotrophic fungi into fungus-feeding bacteria

The root–microbe–soil interface: new tools for sustainable plant production

Summary Measurements of 13 C in fungal sporocarps are useful in assessing mycorrhizal or saprotrophic status. Because 14 C measurements can indicate the age of fungal carbon (C) and mycorrhizal fungi depend closely on recent photosynthate, 14 C may provide additional insight into possible mycorrhizal status. Sporocarps, needles, and litter from Woods Creek, OR, USA together with archived sporocarps were measured for 14 C content by accelerator mass spectrometry. Known mycorrhizal fungi resembled current‐year needles ( Amanita , Cantharellus and Gomphidius ) or atmospheric CO 2 ( Tuber ) in 14 C and indicated an average age of 0–2 yr for incorporated C, whereas saprotrophic genera ( Pleurocybella , Lepiota and Hypholoma ) were composed of C at least 10 yr old. Of genera tentatively considered mycorrhizal from previous work with 13 C, only Otidia and Sowerbyella appeared mycorrhizal from 14 C measurements, whereas Aleuria , Clavulina , Paurocotylis and Ramaria (sensu lato ) consisted of older carbon and were presumably saprotrophic. 14 C clearly separated known mycorrhizal or saprotrophic fungi and indicated 13 C measurements should be interpreted cautiously on species of unknown status. 14 C results for needles and mycorrhizal fungi suggested that C sources other than atmospheric CO 2 may contribute small amounts of C. Possible sources include storage of carbohydrates and amino acids, organic nitrogen uptake, and incorporation of soil‐respired CO 2 by anaplerotic or photosynthetic pathways.