Suillus Granulatus Research Articles

Macro-fungi Community of Lake Ol Bolossat Basin and Associated Riparian Ecosystems in Central, Kenya

Lake OlBolossat, an important wetland in Central Kenya highland currently threatened by anthropogenic activities. In order to conserve biodiversity in this Lake Ecosystem and associated habitats understanding abundance and diversity of different taxa is needed. This study documented macro-fungi diversity of Lake Ol Bolossat basin and its associated riparian ecosystems. The survey revealed 35 macrofungi species distributed across 21 families. Species in family Polyporaceae and Agaricaceae (mainly the puffball) dominated the Lake ecosystems. Woodrotters species (50%) dominated the ecosystem followed by ectomycorrhiza (17%) and cow-dung dwellers (15%). Termite cultivated species and soil dwellers had the lowest representation (9%). Macro-fungi density, species richness and diversity was significantly low in natural grassland and forest remnants compared to introduced and exotic woodlots. Only three species of macrofungi (<i>Termitomyces microcarpus</i>, <i>Ramariopsis kunzei</i> and <i>Datronia mollis</i>) were documented in natural forests remnants. Natural grassland around the lake was mainly dominated by <i>Termitomyces, Lycoperdon</i>, <i>Panaeolus</i> (cowdung), <i>Psilocybe</i> and <i>Agrocybe</i> species (cowdung). Ectomycorrhiza species (<i>Laccaria bicolor, Pisolithus arrhizus, Suillus granulatus, Scleroderma citrinum</i>) dominated introduced and exotic <i>Eucalyptus, Pinus </i>and<i> Acacia mearnsii</i> plantation. This study has revealed wide range of macro-fungi community in Lake Ol Bolossat basin, and adverse effect of degradation on native macro-fungi community. The negative implication of losing macrofungi diversity along Lake OlBolossat ecosystem is discussed.

Antioxidant potential of extracts of three mushroom species collected from the Republic of North Macedonia

The aim of this research was determination of the content of phenols and flavonoids as bioactive compounds in aqueous and ethanolic extracts of three species of mushrooms: Suillus granulatus, Coriolus versicolor, and Fuscoporia torulosa. Furthermore, the antioxidant activity of obtained mushroom extracts was determined. In general, it can be noticed that the phenol content in the three examined macromycetes is higher in the aqueous extract, compared to the ethanolic extract, which shows significant difference (p < .05). The order of antioxidant capacity of aqueous extracts in terms of their DPPH radical-scavenging activity is: Fuscoporia torulosa > Coriolus versicolor > Suillus granulatus, that is, 38.08%–82.64% >38.04%–80.66% >35.99%–75.25%. The aqueous extract of Fuscoporia torulosa belongs to the group of antioxidants with strong antioxidant activity (1.71), while the aqueous extract of Coriolus versicolor belongs to the group of antioxidants with moderate antioxidant activity (0.92). Novelty impact statement The data from this research are of particular importance in terms of finding new, wild species of medicinal and edible mushrooms that contain bioactive components. The antioxidant potential proven in the analyzed mushroom extracts shows that they can be used in the food industry as a substitute for synthetic antioxidant compounds. At the same time, the extract can be a basis for use in alternative medicine.

Native and non-native mammals disperse exotic ectomycorrhizal fungi at long distances from pine plantations

Abstract We aimed to evaluate if exotic ectomycorrhizal fungi from exotic pine plantations disperse through non-native, but also native, mammals in a mountain ecosystem devoid of native ECM plants. Among four non-native and three native mammal species, feces of non-native wild boar (Sus scrofa) and brown hare (Lepus europaeus), and native pampa fox (Lycalopex gymnocercus) were selected to inoculate seedlings of Pinus elliottii. These feces came from two transects in an elevation gradient (1350–2250 m asl) and different distances from a pine plantation (100–6000 m). We show that feces of wild boar, brown hare (non-native), and pampa fox (native) were effective as inoculum for establishing ectomycorrhizal pine seedlings. Through molecular analyses, we determined that two species are mostly consumed and successfully form ectomycorrhizas with pine roots: Suillus granulatus and Rhizopogon pseudoroseolus. We provide novel evidence for the long-distance dispersal of exotic ectomycorrhizal fungi by non-native and native animal vectors.

Successional Change of the Fungal Microbiome Pine Seedling Roots Inoculated With Tricholoma matsutake.

The pine mushroom (Tricholoma matsutake; Agaricales, Tricholomataceae) is an ectomycorrhizal fungus that produces a commercially valuable, edible mushrooms. Attempts to artificially cultivate T. matsutake has so far been unsuccessful. One method used to induce T. matsutake to produce fruiting bodies of in the wild is shiro (mycelial aggregations of T. matsutake) transplantation. In vitro ectomycorrhization of T. matsutake with seedlings of Pinus densiflora has been successful, but field trials showed limited production of fruiting bodies. Few studies have been done to test what happens after transplantation in the wild, whether T. matsutake persists on the pine seedling roots or gets replaced by other fungi. Here, we investigated the composition and the interaction of the root fungal microbiome of P. densiflora seedlings inoculated with T. matsutake over a 3 year period after field transplantation, using high-throughput sequencing. We found a decline of T. matsutake colonization on pine roots and succession of mycorrhizal fungi as P. densiflora seedlings grew. Early on, roots were colonized by fast-growing, saprotrophic Ascomycota, then later replaced by early stage ectomycorrhiza such as Wilcoxina. At the end, more competitive Suillus species dominated the host roots. Most of the major OTUs had negative or neutral correlation with T. matsutake, but several saprotrophic/plant pathogenic/mycoparasitic species in genera Fusarium, Oidiodendron, and Trichoderma had positive correlation with T. matsutake. Four keystone species were identified during succession; two species (Fusarium oxysporum, and F. trincintum) had a positive correlation with T. matsutake, while the other two had a negative correlation (Suillus granulatus, Cylindrocarpon pauciseptatum). These findings have important implications for further studies on the artificial cultivation of T. matsutake.

Productivity of edible fungi in taiga communities

The authors studied edible macrofungi in natural forest communities of middle taiga in Kirov region, Russia. Out of more than 400 macrofungi species known within the area, 5 are rare and being protected, over 20 are used as medicinal, 149 species are considered edible, of which 46 are legally allowed for collection. Local population mostly collects 10-15 species. The largest species variety of economically important macrofungi is found in cowberry and maianthemum-cowberry forest types in which Boletus edulis, B. piniphilus, Leccinum scabrum, L. aurantiacum, L. versipelle, Suillus variegates, Xerocomus subtomentosus, Lactarius rufus, Cantharellus cibarius dominate. Maximum long-term average annual productivity of fruit bodies is marked in young pine lichen forests (127.1 kg/ha), minimum - in mature and overmature bilberry and maianthemum-bilberry spruce forests (24.0 kg/ha). In years of good yield basic dominating species of edible fungi in middle taiga are Suillus granulatus and S. luteus (productivity up to 28-57 kg/ha), Cantharellus cibarius (11-17 kg/ha) and red-cap bolete (up to 21 kg/ha).

Antioxidant Potential and Element Contents of Wild Edible Mushroom Suillus granulatus

Mushrooms are important natural resources in natural ecosystems. They have been used for centuries as a means of food, medicine and religious rituals for humans. In this study, total antioxidant status (TAS), total oxidant status (TOS), oxidative stress index (OSI) and Cr, Cu, Mn, Fe, Ni, Cd, Pb and Zn contents of edible mushroom Suillus granulatus (L.) Roussel were determined. Mushroom samples were collected from Hatay-Antakya (Turkey). Ethanol extracts of mushroom samples were obtained. TAS, TOS and OSI values were measured using Rel Assay kits. Cr, Cu, Mn, Fe, Ni, Cd, Pb and Zn contents were determined by atomic absorption spectrophotometer. As a result of the study, TAS value of S. granulatus was 3.143 ± 0.068 mmol/L, TOS value was 18.933 ± 0.195 µmol/L and OSI value was 0.603 ± 0.007. Cr content of S. granulatus was found to be high. As a result, wild edible mushroom S. granulatus had antioxidant potential.

Biological control potential of ectomycorrhizal fungi against Fusarium circinatum on Pinus patula seedlings

ABSTRACT The South Africa forestry industry, covering ∼1.3 million hectares, is dependent on exotic pine and Eucalyptus species. Nursery seedlings are not inoculated with ectomycorrhizal (ECM) fungi or other beneficial microbes. Fusarium circinatum is an economically important pathogen affecting seedling survival. The purpose of this investigation was to assess the effects of ectomycorrhizal fungal inoculation on Pinus patula seedling growth and resistance to the fungal pathogen F. circinatum. Explants from ECM basidiocarps, collected from Pinus stands, were plated onto MMN medium to obtain isolates that were then verified via DNA extraction and PCR amplification and sequencing of the ITS rDNA region. These isolates were identified as Boletus edulis f. reticulatus, Lactarius quieticolor, Suillus granulatus and an unknown Suillus species. P. patula growth in the presence of the pathogen F. circinatum was significantly increased and promoted by the L. quieticolor and Suillus isolates. Preventative inoculation of seedlings in the nursery using these isolates would ensure the production of stronger, healthier plants that would be more resistant to F. circinatum infection, increasing survival in the plantation.

Evaluation of umami taste components of mushroom (Suillus granulatus) of different grades prepared by different drying methods

Suillus granulatus is a valuable wild edible mushroom with a strong umami taste. Different grades of S. granulatus were dried by different methods, including natural air drying (ND), hot air drying (HAD), vacuum drying (VD), and freeze drying (FD). Results showed that VD samples of all grades had the highest equivalent umami concentration (EUC) value (P<0.05). The second grade of ND samples showed the highest EUC value (P<0.05). The first grade of HAD samples showed the highest EUC value (P<0.05). The third grade of FD samples showed the highest EUC value (P<0.05). The third grade of VD samples had a higher EUC value than the other grades of samples dried by VD. Electronic tongue results indicated no significant differences between samples of all grades dried by all methods. Thus, umami taste components are affected by drying method and grade. VD is an appropriate drying method for all sample grades. ND, HAD, and FD are suitable for second-, first-, and third-grade samples, respectively.

The Influence of Contrasting Microbial Lifestyles on the Pre-symbiotic Metabolite Responses of Eucalyptus grandis Roots

Plant roots co-inhabit the soil with a diverse consortium of microbes of which a number attempt to enter symbiosis with the plant. These microbes may be pathogenic, mutualistic, or commensal. Hence, the health and survival of plants is heavily reliant on their ability to perceive different microbial lifestyles and respond appropriately. Emerging research suggests that there is a pivotal role for plant root secondary metabolites in responding to microbial colonization. However, it is largely unknown if plants are able to differentiate between microbes of different lifestyles and respond differently during the earliest stages of pre-symbiosis (i.e., prior to physical contact). In studying plant responses to a range of microbial isolates, we questioned: (1) if individual microbes of different lifestyles and species caused alterations to the plant root metabolome during pre-symbiosis, and (2) if these early metabolite responses correlate with the outcome of the symbiotic interaction in later phases of colonization. We compared the changes of the root tip metabolite profile of the model tree Eucalyptus grandis during pre-symbiosis with two isolates of a pathogenic fungus (Armillaria luteobubalina), one isolate of a pathogenic oomycete (Phytophthora cinnamomi), two isolates of an incompatible mutualistic fungus (Suillus granulatus), and six isolates of a compatible mutualistic fungus (Pisolithus microcarpus). Untargeted metabolite profiling revealed predominantly positive root metabolite responses at the pre-symbiosis stage, prior to any observable phenotypical changes of the root tips. Metabolite responses in the host tissue that were specific to each microbial species were identified. A deeper analysis of the root metabolomic profiles during pre-symbiotic contact with six strains of P. microcarpus showed a connection between these early metabolite responses in the root with later colonization success. Further investigation using isotopic tracing revealed a portion of metabolites found in root tips originated from the fungus. RNA-sequencing also showed that the plant roots undergo complementary transcriptomic reprogramming in response to the fungal stimuli. Taken together, our results demonstrate that the early metabolite responses of plant roots are partially selective toward the lifestyle of the interacting microbe, and that these responses can be crucial in determining the outcome of the interaction.

MUSHROOM DIVERSITY IN SHAKI DISTRICT OF AZERBAIJAN

Mushroom diversity in Shaki district of Azerbaijan was studied during 2013-2018. Totally 346 specimens were collected and identified based on the morphologically main diagnostic features. Phenotypic characters, as well as microscopic features (size, shape, color of spores) were considered. In total 111 taxa (106 species, three forms and two variations) belonging to 67 genera, 32 families and 11 orders of Ascomycota and Basidiomycta were identified in view of the latest taxonomic and nomenclature changes. Two taxa Morchella esculenta var. rotunda and Suillus luteus f. albus represent new records for Azerbaijan. Ecological groups of mushrooms were reflected. Amanita fulva, A. pantherina, A. vaginata, Apioperdon pyriforme, Boletus edulis, B. reticulatus, Bovista plumbea, Caloboletus radicans, Cantharellus cibarius, C. subalbidus, Chlorophyllum rhacodes, Coprinopsis atramentaria, Hymenopellis radicata, Hypholoma fasciculare, Lactarius piperatus, Leccinum scabrum, Lepiota cristata, Lycoperdon umbrinum, Morchella esculenta, Mycena crocata, M. pura, Russula foetens, R. rosacea, Sarcoscypha coccinea, Suillus granulatus, S. luteus, Suillellus luridus and Tricholoma ustale were frequently found in the district. The rare species found in the studied area were Butyriboletus regius, Cortinarius triumphans, Clavariadelphus pistillaris, Crepidotus cesatii, Lactarius deliciosus, Morchella crassipes, Otidea onotica, Suillellus queletii and Tuber aestivum. Species variation was observed to increase along the elevation gradient, starting from the low mountain zone. Abundance of species decreases in the middle-upper mountain zone. Species distribution patterns along the elevation gradients are affected by mountain range peculiarities and climate warming. Numerous species have been recorded in more than one altitude. Use possibility of fungi is also elucidated.

Performance of Quercus suber L. at nursery stage\u2014application of two bio-inoculants under two distinct environments

Key messageDespite the fact that the technique of application of bioinoculants improved the quality ofQuercus suberL. seedlings produced in nurseries, these benefits are dependent on the ecological conditions of the site and the composition of the applied inoculum, which interferes with the profile of the local fungal community.ContextQuercus suber L. plays a key ecological and socio-economical role in the Iberian Peninsula. Symbiotic ectomycorrhizal fungi-ECM are crucial partners of several tree species, and assessing the efficacy of bioinoculants at nursery stage helps devising tools to increase plant resilience.AimsThe aim of this study was to compare the effects of two inocula formulations of mixed ECM fungi and bacteria on the quality of seedlings produced in two forest nurseries, differing in environmental conditions and forest embedment.MethodsQuercus suber L. seedlings were inoculated with a commercial product containing Pisolithus tinctorius (Pers) Coker & Couch, Scleroderma sp., and six bacterial species and with a non-commercial fungal and bacterial dual inoculum (Suillus granulatus (L.) Roussel + Mesorhizobium sp.). Biometric and nutritional parameters and morphological quality indexes were determined on seedlings. The ECM community was assessed by denaturing gradient gel electrophoresis and cloning-sequencing.ResultsIn both nurseries, the seedling quality index in inoculated was up to 2-fold higher than in non-inoculated seedlings. Plant biomass differed significantly among nurseries. The inoculum influenced the profile of the fungal community. S. granulatus and P. tinctorius persisted for 6 months in the inoculated seedlings.ConclusionThe nursery ecosystem influenced plant growth. Inoculation treatments increased plant performance; however, the dual inoculum resulted in more consistent improvements of Q. suber at nursery stage, highlighting the importance of inocula selection.

Structural characterization, antioxidant activity, and immunological activity in vitro of polysaccharides from fruiting bodies of Suillus granulatus

Two polysaccharide fractions, SGP I-b and SGP II-b, were purified from the fruiting bodies of Suillus granulatus. The assayed relative molecular masses of SGP I-b and SGP II-b were approximately 17.31 and 10.16 kDa, respectively. SGP I-b consisted of fucose, mannose, glucose, and galactose, whereas SGP II-b consisted of rhamnose, fucose, mannose, glucose, and galactose. The structures of SGP I-b and SGP II-b were preliminarily analyzed through methylation analysis and nuclear magnetic resonance spectroscopy. The results of in vitro antioxidant assays revealed that SGP II-b demonstrated good scavenging ability for hydroxyl and DPPH radicals but poor reduction capacity and scavenging for superoxide anions. SGP I-b did not exhibit any significant antioxidant activities. SGP II-b could also significantly increase lymphocyte proliferation in vitro, however, SGP I-b had no significant effect. Practical applications Suillus granulatus is a wild, edible medicinal fungus distributed in Northeastern China. S. granulatus polysaccharides (SGP) already be prove have special bioactivities. In the current study, SGP were purified and characterized, and the antioxidant activities and immunomodulatory effects were also assayed. Our work will contribute to the utilization of SGP as natural antioxidants and/or immunity-enhancing agents in food and pharmaceutical industries.

In vitro GROWTH OF ECTOMYCORRHIZAL FUNGI ASSOCIATED WITH Pinus radiata PLANTATIONS IN CHILE

A comparative study of in vitro growth of three species of ectomycorrhizal fungi (ECMF) (Rhizopogon luteolus, Suillus granulatus and Suillus luteus) was performed. Fungal material was collected in adult Pinus radiata plantations. Isolation and purification of the strains were performed on potato-dextrose-agar medium and the evaluation of the radial growth rate and the increase in mycelial biomass, under different culture conditions, was performed on the Modified Melin Norkrans growth medium. The effects of temperature (24, 28 and 32 ºC) and pH (4.8, 5.3, 5.8, 6.3 and 6.8) of the growth medium were tested for the three fungal species in two independent assays. The results indicate that the temperature had a significant effect on the radial growth rate (RG) and mycelial biomass increase (MB) in all of the evaluated fungal species. The highest RGR and MBI were recorded in R. luteolus, and the lowest values for these variables were registered in S. luteus. Rhizopogon luteolus had the highest sensitivity to pH changes. Meanwhile, there was no pattern in S. granulatus and S. luteus growth response under different pH conditions. When cultivated in vitro, the three studied species of ECMF presented adaptation, exponential, declining and stationary growth phases. The in vitro growth responses recorded in the present study showed the great potential of R. luteolus to be used in future programs using mycorrhizal inoculation in the production of Pinus radiata trees in nurseries in Chile.

アカマツ(Pinus densiflora)の種子サイズがチチアワタケ(Suillus granulatus)による菌根形成と実生の初期成長に及ぼす影響

アカマツ(Pinus densiflora)の種子サイズがチチアワタケ(Suillus granulatus)による菌根形成と実生の初期成長に及ぼす影響

Biochemical Responses of Ten Ectomycorrhizal Fungal Isolates to Manganese

Manganese (Mn) is one of the heavy metals that pollute the environment. However, there are still few studies concerning Mn pollution. Our study focused on the ectomycorrhizal fungi (EMF), an important organism in the forest. We selected ten isolates of EMF, including Pt.2 (Pi solithus tinctorius 2), Cg.1 (Cenococcum geophilum 1), Br (Boletus reticulatus), Sb (Suillus bovinus), Pt.chdx (P. tinctorius chdx), Pt.104 (P. tinctorius 104), Sg (Suillus granulatus), Av (Amanita virgineoides), Sl.1 (Suillus luteus 1), and Sl.chdx (S. luteus chdx), to investigate their responses to Mn stress (0 to 3000 mg L−1) on liquid MMN medium. EMF isolates showed different responses to Mn stress after 60 days growth. According to their growth, they were classified into three groups: sensitive, moderately sensitive, and tolerant. Three isolates showed tolerance to Mn stress. The mycelia of the four sensitive EMF isolates grew slowly along with the increasing Mn level, and the growth was significantly inhibited in 3000 mg L−1 Mn. The accumulation of Mn in EMF mycelium was increased and the secretion of oxalic acid was stimulated by the increasing Mn concentration for all isolates. However, the sensitive isolates secreted significantly more oxalic acid than the tolerant isolates. A scanning electron microscope showed that hyphae were distorted and severely swollen and a transmission electron microscope revealed that Mn enriched in the cytoplasm and organelles of hyphae cells when EMF grew under 3000 mg L−1 Mn stress. In addition, we found that antioxidative enzyme activities, glutathione S-transferase (GST), and superoxide dismutase (SOD) were higher under the stress of Mn. In conclusion, we identified three isolates (Pt.2, Pt.104, and Br) that showed high Mn tolerance. This might demonstrate the great potential of those EMF in the reforestation of Mn mine lands.

Co-invasive exotic pines and their ectomycorrhizal symbionts show capabilities for wide distance and altitudinal range expansion

We asked if exotic Pinus elliotti seedlings can survive and form ectomycorrhizas at higher elevations and long distances from their current range, and which ECM partners disperse to these soils. We selected three plots at four grassland sites along an altitudinal gradient (900, 1600, 2200, and 2700 m asl) established at c. 110, 3000, 6000, and 9000 m from the closest pine plantation, respectively. We combined field experiments with glasshouse assays to assess survival and ECM fungi in roots and soils. A pine plantation close to the lowest site was also selected for DNA metabarcoding of soils. Pine seedlings survived at all altitudes but not all formed mycorrhizas. They formed mycorrhizas with Suillus granulatus at 900, 1600, and 2200 m asl (i.e. up to 6000 m from the closest pine plantation), and with Rhizopogon pseudoroseolus and Thelephora terrestris at lower altitudes and distances. Twelve ECM fungal OTUs were found in grasslands and 34 were detected in the pine plantation. Although richness and abundance of ECM fungi decreased with increasing distance from the pine plantation, there was at least one non-native ECM fungal species present in each sampling site, even at 2700 masl and 9000 m distance from the closest plantation. This study provides evidence that the availability of suitable fungal symbionts might constrain but not hinder the expansion of a pine species over wide distances and altitudinal zones even in areas with no native ECM fungi.

Effects of temperature, pH and carbon and nitrogen sources on growth of in vitro cultures of ectomycorrhizal isolates from Pinus heldreichii forest

Aim of study: This study aims to provide basic information about physiological characteristics of isolates of Lactarius deliciosus (L.) Gray, Russula sanguinaria (Schumach.) Rauschert, Suillus collinitus (Fr) Kuntze, Suillus granulatus (L.) Rousell, Tricholoma batchii Gulden and Tricholoma imbricatum (Fr.) Kumm.Area of study: The isolates are obtained from Pinus heldreichii H. Christ forest in the south-eastern part of Montenegro.Material and methods: The isolates were molecularly characterised by internal transcribed spacer (ITS) sequencing and restriction fragment length polymorphism (RFLP) analysis. The effects of different temperatures (20, 22, 25°C), pHs (4, 4.5, 5.2, 5.8, 6.5, 7.5), and carbon (glucose, sucrose, dextrin, arabinose, xylose and starch) and nitrogen (NH4+, NO3- and protein) sources on their growth were examined under laboratory conditions.Main results: The studied factors established significant differences in the development of isolates. Isolates of R. sanguinaria, L. deliciosus and both Suillus, were characterised by faster growth at 22°C, while Tricholoma isolates grew faster at 25°C. S. granulatus, S. collinitus and T. imbticatum isolates grew well at lower pH values (4 - 5.2), while L. deliciosus, R. sanguinaria and T. bachii exhibited faster growth at pHs between 5.8 and 6.5. The examined isolates were able to utilize various carbohydrates as carbon sources. The biggest mycelial growth was characterised for sucrose, then glucose, dextrin, arabinose, starch and xylose. They grew on all examined nitrogen sources, while the biggest mycelia growth was achieved on ammonium, followed by nitrate and protein. Those characteristics varied amongst the species.Research highlights: Information about physiological characteristics of Tricholoma, Lactarius, Russula, as well as Suillus, are sparse. Hence, the data obtained in this study could contribute to the understanding of their function in ecosystems.

Species-specific roles of ectomycorrhizal fungi in facilitating interplant transfer of hydraulically redistributed water between Pinus halepensis saplings and seedlings

Interplant transfer of hydraulically redistributed water (HRW) can take place via mycorrhizal hyphal networks linking the roots of neighboring plants. We conducted a mesocosm experiment to evaluate the influence of reduced extraradical hyphal lengths on interplant HRW transfer. Ectomycorrhizal Pinus halepensis saplings and seedlings were grown together in two-compartment mesocosms (fungicide-treated or control), and deuterium-labeled water was supplied to the taproot compartment (accessible to sapling taproots) during a 9-day soil drying cycle. Upper soil water contents and seedling water potentials at the end of the drying cycle were lower in fungicide-treated than in control mesocosms. The stem water δD values of seedlings increased (marginally) with increasing soil hyphal length in both treatments separately, suggesting that interplant HRW transfer was at least partly mediated by fungal hyphae. In fungicide-treated mesocosms, the difference in δD values between the stem water of seedlings and upper soil water decreased sharply with increasing soil hyphal length, supporting a key role of ectomycorrhizal fungi (EMF) in interplant HRW transfer at low soil hyphal densities. However, two dominant EMF morphotypes differing in their water repellence properties and hyphal exploration types (Thelephora terrestris and Suillus granulatus) had contrasting impacts on hydraulic redistribution patterns, as only the EMF producing hydrophilic hyphae (T. terrestris) enhanced HRW transfer between pine saplings and seedlings. Changes in the abundance and/or composition of EMF communities in response to anthropogenic disturbance or climate change could affect facilitative plant interactions through alterations of interplant HRW transfer.

Genet Variation of Ectomycorrhizal Suillus granulatus Fruiting Bodies in Pinus strobus Stands

The genets of Suillus granulatus in a Pinus strobus stand (13 m × 60 m) were identified using random amplified polymorphic DNA molecular markers and the DNA of mushrooms that fruited for two years, and variations in genet size and distribution were analyzed. From a total of 116 mushrooms, 73 genets were identified and were grouped into three locations. The genets of mushrooms in close proximity differed from each other. The genet sizes varied at any of the three locations. The lengths of the identified genets in the pine stand ranged from 0.09 to 2.90 m. The average number of mushrooms per genet was 1.2 to 2.3, and the percentage of genets that were represented by a single mushroom was 44% to 94%. This variation in the genets of mushrooms in close proximity suggests that the ectomycorrhizal mycelial bodies of S. granulatus propagated sexually by fusing haploid spores derived from the mushrooms gills with below-ground mycelia. Therefore, it is necessary further to investigate the formation of new genets through spores in ectomycorrhizal fungal colonies.

Optimization Extraction Process of Polysaccharides from Suillus granulatus and Their Antioxidant and Immunological Activities In vitro.

Background:Suillus granulatus is an edible and medicinal fungus in China. S. granulatus polysaccharide (SGP) was considered as the main bioactivity compounds in S. granulatus. Therefore, the extraction of SGP and their antioxidant activities were studied in this work.Materials and Methods:Fruiting bodies of S. granulatus were purchased from a local market (Fushun, China). Response surface methodology was adopted to optimize the extraction conditions of SGP. The antioxidant and immunological activities in vitro were also assayed.Results:The extraction of SGP was optimized by a Box–Behnken design. The optimal conditions for the extraction of polysaccharides were as follows: Pre-extraction time, 2 h; extraction temperature, 94°C; ratio of water to raw material, 25; and extraction frequency, 2. Under these conditions, the experimental yield of polysaccharides was 5.38% ±0.15%, which agreed with the predicted yield. The antioxidant assay in vitro showed that SGPs had relatively high scavenging ability for hydroxyl radicals and higher scavenging ability for 1,1-diphenyl-2-picrylhydrazyl radical. However, the scavenging ability of SGPs for superoxide anion radical and reducing power was relatively low. The polysaccharides also significantly increased splenocyte proliferation in vitro.Conclusion:SGP possessed good antioxidant and immunological activities in vitro and explored as a novel natural antioxidant or functional food.SUMMARY The predictive model of Suillus granulatus polysaccharide (SGP) extraction is adequate for the extraction processSGP possessed a good antioxidant activity in vitroLymphocyte proliferation in vitro was significantly increased by SGPPictorial abstract (in MS Powerpoint Format) is submitted as a separated file in the online submission system. Abbreviation used: SGP: Suillus granulatus polysaccharides, RSM: Response surface methodology, BBD: Box–Behnken design, Vc: Ascorbic acid, DPPH: 1,1-diphenyl-2-picrylhydrazyl, MTT: 3-(4,5- dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, ConA: Concanavalin A, LPS: lipopolysaccharide, RPMI-1640: Roswell Park Memorial Institute-1640.