Yutaka Tamai

Buried charcoal layer and ectomycorrhizae cooperatively promote the growth of Larix gmelinii seedlings

Charcoal produced by fire on the soil surface mixes into the soil over time and is heterogeneously distributed within the soil profile in post-fire forests. To determine how different patterns of vertical distribution of charcoal and ectomycorrhizal formation affect the growth of Larix gmelinii (Gmelin larch) in post-fire forests, we conducted a model experiment in the pots. In this study, pots with a layer of charcoal in the middle of the soil profile promoted growth of the root system of the seedlings significantly more than did pots with no charcoal or with charcoal scattered throughout the soil. Along with the development of the root system, above-ground biomass and total biomass were also increased. Furthermore, in addition to the positive effects of charcoal in the soil, there were also strong positive effects on the growth of seedlings from ectomycorrhizal root formation. As a result, the largest above-ground biomass and total biomass were found for seedlings grown in layered charcoal with ectomycorrhizae. Furthermore, the highest phosphorus concentration in needles was also found for seedlings grown in layered charcoal with ectomycorrhizae. This is attributable to the frequent contact of roots with charcoal in the middle layer of the soil and the utilisation of phosphate by ectomycorrhizae. This suggests that buried and layered charcoal occurring in patches in post-fire stands may provide a suitable habitat for the growth of Gmelin larch seedlings.

A Phytochemical in the Edible Tamogi-take Mushroom (Pleurotus cornucopiae), D-Mannitol, Inhibits ACE Activity and Lowers the Blood Pressure of Spontaneously Hypertensive Rats

D-Mannitol, one of the main phytochemicals of the edible Tamogi-take mushroom (Pleurotus cornucopiae), was found to inhibit an angiotensin I converting enzyme (ACE). The antihypertensive effect of D-mannitol and a hot water extract of Tamogi-take mushroom was demonstrated in spontaneously hypertensive rats (SHR) by oral administration.

Arbuscular mycorrhizal colonization of tree species grown in peat swamp forests of Central Kalimantan, Indonesia

Abstract Arbuscular mycorrhizas improve the growth and nutrient uptake of plants and are formed in 80% of all land plants. Little information is available on the status of arbuscular mycorrhizas in tropical soils. The objective of this study was to clarify mycorrhizal colonization of tree species grown in tropical peat soils. Seedlings of 22 tree species in 14 families grown in a peat swamp forest of Central Kalimantan, Indonesia were collected in 2000 and 2001. Roots were stained with 0.05% aniline blue and arbuscules, vesicles and internal hyphae were observed under a compound microscope. Seventeen of 22 species showed arbuscular mycorrhizal colonization. Arbuscular mycorrhizal colonization was observed for the first time in roots of Shorea teysmanniana, Shorea balangeran, Shorea uliginosa (Dipterocarpaceae), Calophyllum sclerophyllum, Calophyllum soulattri (Guttiferae), Cratoxylum arborescens (Guttiferae), Tetramerista glabra (Tetrameristaceae), Palaquium gutta (Sapotaceae), Melastoma melabathricum (Melastomataceae), Gonystylus bancanus (Thymelaeaceae), Hevea brasiliensis (Euphorbiaceae) and Campnosperma auriculatum (Anacardiaceae). C. soulattri, C. arborescens, G. bancanus, Acacia mangium, M. melabathricum and H. brasiliensis showed a percentage mycorrhizal colonization of 50% or higher. No arbuscular mycorrhizal colonization was found in Hopea mengarawan (Dipterocarpaceae), Koompassia malacensis (Caesalpiniaceae), Tristaniopsis whiteana (Myrtaceae), Combretocapus rotundatus (Rhizophoraceae) and Dyera costulata (Apocynaceae). It is suggested that inoculation of arbuscular mycorrhizal fungi can improve the early growth of some tree species grown in peat swamp forests and this will be expected as a key technology to rehabilitate disturbed peatlands.

Investigation of relationships between cell and pulp properties in Eucalyptus by examination of within-tree property variations

Abstract Relationships between cell and pulp properties were investigated by examining the within-tree property variations in Eucalyptus camaldulensis and Eucalyptus globulus. Properties investigated included proportions of ray and axial parenchyma, thickness of cell walls and cell wall percentages. The characteristics of the ray and axial parenchyma (their proportions and wall thickness) were found to have a significant influence on all measured pulp properties, including paper strength properties. Multiple regression of pulp properties in relation to cell properties revealed that nearly all measured pulp properties were explained by cell properties at the 1% significance level. It was concluded, therefore, that all cell types are important for predicting pulp properties, and it is strongly recommended that tree breeding programs for Eucalyptus include the measurement of all cell types.

A gene encoding a hydrophobin, fvh1, is specifically expressed after the induction of fruiting in the edible mushroom Flammulina velutipes.

Abstract. A cDNA clone of the gene fvh1 was previously isolated from a preprimordial cDNA library made from the basidiomycete Flammulina velutipes. Sequence analysis showed that fvh1 encoded for a hydrophobin, a small fungal protein usually secreted by filamentous fungi. FVH1 had a highly conserved arrangement of eight cysteine residues, a putative N-terminal signal sequence and a hydropathy pattern characteristic of class I hydrophobin. A genomic fvh1 clone was isolated from a F. velutipes genomic DNA library and sequenced. Several putative promoter elements and three small introns of fvh1 were identified in this clone. Southern blot analysis of genomic DNA showed that fvh1 was a single copy gene. Northern analysis indicated that fvh1 was specifically and abundantly expressed in mycelia after the induction of fruiting and during fruit body initiation. It was not expressed in mycelia before the induction of fruiting or in mature fruit bodies.

Inoculation with the ectomycorrhizal fungi Pisolithus arhizus and Scleroderma sp. improves early growth of Shorea pinanga nursery seedlings

Abstract.Trees of the family Dipterocarpaceae are the dominant trees in Southeast Asian tropical forests where they play an important ecological role and are also important commercially. An experiment was conducted to determine the effect of ectomycorrhizal fungi on the growth of dipterocarp species in peat soils. Seedlings of Shorea pinanga were inoculated with spores of two ectomycorrhizal fungi, Pisolithus arhizus and Scleroderma sp. were grown in pots containing sterilized peat soil for 7 months. The percentage of ectomycorrhizal colonization on S. pinanga exceeded 86%. Colonization of S. pinanga roots by ectomycorrhizal fungi resulted in increased shoot height, stem diameter, number of leaves, and shoot fresh and dry weight. Survival rates of S. pinanga were greater for inoculated seedlings than control seedlings. These results suggest that inoculation of ectomycorrhizal fungi can improve the early growth of S. pinanga grown in tropical forests and that this technique will accelerate the rehabilitation of degraded dipterocarp forests.

Mycorrhizal associations in woody plant species at the Mt. Usu volcano, Japan

We investigated the association between ectomycorrhizal (ECM) and arbuscular mycorrhizal (AM) fungi and pioneer woody plant species in areas devastated by the eruption of Mt. Usu, Japan, in 2000. We observed eight woody plant species at the research site, most of which were associated with ECM and/or AM fungi. In particular, dominant woody plant species Populusmaximowiczii, Salixhultenii var. angustifolia and Salixsachalinensis were consistently associated with ECM fungi and erratically associated with AM fungi. We found one to six morphotypes in the roots of each ECM host and, on average, two in the roots of each seedling, indicating low ECM fungal diversity. ECM colonization ranged from 17 to 42% of root tips. Using morphotyping and molecular analyses, 15 ECM fungi were identified. ECM fungi differed greatly between hosts. However, Laccaria amethystea, Hebelomamesophaeum, Thelephoraterrestris and other Thelephoraceae had high relative colonization, constituting the majority of the ECM colonization in the roots of each plant species. These ECM fungi may be important for the establishment of pioneer woody plant species and further revegetation at Mt. Usu volcano.

Chemical constituents ofInonotus obliquus II: a new triterpene, 21,24-cyclopentalanosta-3β,21,25-triol-8-ene from sclerotium

A new lanostane-type triterpene with a cyclopentanol partial structure in the side chain was isolated from the sclerotium of the wood rotting fungusInonotus obliquus along with four known compounds: lanosterol, inotodiol, trametenolic acid, and 3β-hydroxy-8,24-dienlanosta-21,23-lactone. The new compound was determined to be 21,24-cyclopentalanosta-3β,21,25-triol-8-ene by spectroscopic analyses.

Ectomycorrhizal colonization and growth of the hybrid larch F1 under elevated CO2 and O3

We studied the colonization of ectomycorrhizal fungi and species abundance of a hybrid larch (F1) under elevated CO₂ and O₃. Two-year-old seedlings were planted in an Open-Top-Chamber system with treatments: Control (O3 < 6 nmol/mol), O₃ (60 nmol/mol), CO₂ (600 μmol/mol), and CO2 + O₃. After two growing seasons, ectomycorrhiza (ECM) colonization and root biomass increased under elevated CO₂. Additionally, O₃ impaired ECM colonization and species richness, and reduced stem biomass. However, there was no clear inhibition of photosynthetic capacity by O₃. Concentrations of Al, Fe, Mo, and P in needles were reduced by O₃, while K and Mg in the roots increased. This might explain the distinct change in ECM colonization rate and diversity. No effects of combined fumigation were observed in any parameters except the P concentration in needles. The tolerance of F1 to O₃ might potentially be related to a shift in ECM community structure.

Effect of moisture content of a wood matrix on a small-scale biodegradation system for organic solid waste

The optimum working moisture content of a wood matrix for the garbage automatic decomposer-extinguisher (GADE) machine was investigated using a small-scale degradation reactor. A formula feed for rabbits was used as the model waste. The degradation experiment was conducted under controlled conditions such as moisture content, environmental temperature, and airflow rate. The degradation rate was estimated precisely from weight loss and the CO2 evolution rate. The degradation rate were nearly constant at a moisture content of 30%–80% on a-wet-weight basis. Microorganisms from the environment propagated in the reactor with no inoculums added. The number of microorganisms showed a trend similar to that of the degradation rate. The microorganism community changed according to the moisture content of the matrix and were considered to attain a constant degradation rate at a wide range of moisture content of a matrix.