Japanese Birch Research Articles

Intraspecific Variation in Three Species of Semudobia (Diptera: Cecidomyiidae) Forming Fruit Galls on Betula (Betulaceae) in the Holarctic Region

We analyzed the Folmer fragment of the mitochondrial COI gene of three closely related species of Semudobia (Diptera: Cecidomyiidae): S. betulae (Winnertz), S. tarda Roskam, and S. skuhravae Roskam. These species form fruit galls on different birch species (Betula, Betulaceae) in the Holarctic Region. In Japan, larvae of S. betulae and S. tarda were collected from the native Japanese birch, B. platyphylla, whereas S. skuhravae was collected from the eastern Palearctic birch, B. ermanii. In the Netherlands, the three species were collected from intermediate forms between the Eurasian endemic birches, B. pendula and B. pubescens. Additional sequences of Canadian and European S. betulae and S. skuhravae were obtained from the Barcode of Life Data system (BOLD). In a maximum likelihood analysis, the individuals of each species formed strongly supported clades, but genetic divergence was high within each clade indicating species complexes. European and Canadian individuals of S. betulae and S. skuhravae each formed a single clade with low intraspecific variation, suggesting that these species were introduced together with their hosts to North America. In contrast, Japanese individuals of the three Semudobia species were remarkably distant from European and Canadian individuals, indicating that they have been isolated genetically for a long period on their native eastern Palearctic and Japanese hosts.

924. BETULA CHICHIBUENSIS

SummaryThe very rare Japanese birch, Betula chichibuensis Hara, is described and illustrated. It has become widely available since its 1986 introduction from seed, from a breeding population derived from the then single known wild stand. In 2015 it was reintroduced from further, recently discovered, wild populations.

Proteomic Analysis of Responsive Proteins Induced in Japanese Birch Plantlet Treated with Salicylic Acid.

The present study was performed to unravel the mechanisms of systemic acquired resistance (SAR) establishment and resistance signaling pathways against the canker-rot fungus (Inonotus obliquus strain IO-U1) infection in Japanese birch plantlet No.8. Modulation of protein-profile induced by salicylic acid (SA)-administration was analyzed, and SA-responsive proteins were identified. In total, 5 specifically expressed, 3 significantly increased, and 3 significantly decreased protein spots were identified using liquid chromatography/tandem mass spectrometry (LC/MS/MS) and the sequence tag method. These proteins were malate dehydrogenase, succinate dehydrogenase, phosphoglycerate kinase, diaminopimalate decarboxylase, arginase, chorismate mutase, cyclophilin, aminopeptidase, and unknown function proteins. These proteins are considered to be involved in SAR-establishment mechanisms in the Japanese birch plantlet No 8.

Plasticity Analysis of the Strain in the Tangential Direction of Solid Wood Subjected to Compression Load in the Longitudinal Direction

Uniaxial compression tests in the grain (longitudinal) direction of solid wood were conducted using specimens of Sitka spruce and Japanese birch. The nonlinear stress-strain behavior was analyzed using plasticity theory, which is typically applied to ductile materials such as metals. The relationship between the longitudinal and tangential directions obtained from the experimental results showed nonlinearity, as predicted based on plasticity theory. Nevertheless, it was more pronounced in the experimental results than in the plasticity analysis.

Proteome analysis of infection-specific proteins from Japanese birch (Betula platyphylla var. japonica) plantlet No.8 infected with Inonotus obliquus strain IO-U1

This study aimed to identify the proteins produced specifically in Betula platyphylla var. japonica plantlet No. 8 by infection with Inonotus obliquus strain IO-U1. Sterile Japanese birch plantlets were infected with the fungus, and the protein samples obtained at 2 days post-infection were subjected to two-dimensional electrophoresis to detect infectionspecific proteins. The specific proteins were analyzed using MALDI-TOF-MS and identified by peptide mass fingerprinting with MASCOT software. Among the 735 protein spots detected in the infected plantlets, 169 spots were recognized as infection-specific proteins. Of these spots, 91 were analyzed using MALDI-TOF-MS, with two heat shock proteins (Hsp70 and Hsp60) being identified as infection-specific proteins. Hsp70 and Hsp60 may cooperate to refold proteins that were denatured by the infection of I. obliquus strain IO-U1 in the birch plantlets. It is suggested that these proteins are expressed in B. platyphylla plantlet No. 8 by infectious stress with I. obliquus strain IO-U1.

Anatomical and histochemical characteristics of Japanese birch (Tohoku) plantlets infected with the Inonotus obliquus IO-U1 strain

Host-pathogen interactions were investigated on a Japanese birch (Betula platyphylla var. japonica, Tohoku) plantlet after infection with a canker-rot fungus, the Inonotus obliquus IO-U1 strain. For a time-course study, intact, wounded, and infected plantlets were collected from 2 h to 30 days after treatment. Notable changes were observed morphologically in the treated portion of wounded and infected plantlets. Phenolics first deposited at the cut margin and subsequently in vessels after 4 h of infection. Their deposition extended to other xylem elements, the cortex, and the pith with an increase in the infection period. Phenolics deposition was extensive at 10 days post-inoculation (dpi), when most of the cells were entirely filled with phenolics. A necrophylactic periderm (NP) was formed at the junction of the original periderm with a layer of 2-4 new phellem cells at 30 dpi. Based on the results obtained, phenolics deposition and NP formation are considered to occur as infection-induced responses in Tohoku birch plantlets infected with I. obliquus IO-U1.

Compressive deformation of wood impregnated with low molecular weight phenol formaldehyde (PF) resin IV: Species dependency

Flat-sawn specimens of eight wood species, albizia (Paraserianthes falkata, 0.23 g/cm3), Japanese cedar (Cryptomeria japonica, 0.31 g/cm3), red lauan (Shorea sp., 0.36 g/cm3), European spruce (Picea abies, 0.44 g/cm3), Douglas fir (Pseudotsuga douglasii, 0.50 g/cm3), elm (Ulmus sp., 0.51 g/cm3), Japanese beech (Fagus crenata, 0.64 g/cm3), and Japanese birch (Betula maximowicziana, 0.71 g/cm3), were impregnated with low molecular weight phenol-formaldehyde (PF) resin and their compressive deformations were compared. The volume gain (VG) and weight gain due to 20% resin solution impregnation were different among species. Furthermore, the specific volume gain (VG/specific gravity), indicating the degree of swelling of the cell wall, also varied from 17.7% for European spruce to 26.4% for elm. Oven-dried specimens of each species were compressed using hot plates fixed to an Instron testing machine. The deformation behavior of resin-impregnated wood up to 10MPa was significantly different among the species. Stress development during cell wall collapse for low density wood was minimal. As a consequence, a significant increment of density occurred up to 2MPa for low density wood such as albizia and Japanese cedar. When PF resin-impregnated wood was compressed up to 2MPa and the pressure was kept constant for 30min, the density of Japanese cedar reached 1.18g/cm3, about 30% higher than the density of compressed Japanese birch, which possesses an original density that is 2.5 times higher than that of Japanese cedar. The mechanical properties of resin-impregnated wood, especially low density wood, increased with density. Hence, it is manifested that low density wood species have an advantage as raw materials for obtaining high-strength wood at low pressing pressure.

The present condition and the improvement method of the stand of Japanese birch, Betula platyphylla var. japonica, along Route 273, in Daisetsuzan National Park, central Hokkaido

The present condition and the improvement method of the stand of Japanese birch, Betula platyphylla var. japonica, along Route 273, in Daisetsuzan National Park, central Hokkaido

Effects of Element Size and Orientation in the Production of High Strength Resin Impregnated Wood Based Materials

Summary The effects of low molecular weight phenolic resin impregnation and high pressure hot pressing (150°C, 30–100 MPa) on the physical and mechanical properties of wood were first investigated by using sawn wood prepared from a block of Japanese birch (Betula meximowicziana). Subsequently, the effects of element size and orientation were examined by using sliced veneers, particles and powder prepared from the remaining portion of the block. Due to the combination of resin impregnation and hot pressing under high pressure, the specific bending strength at 20°C and 65% RH of sawn wood increased 50% accompanied by enormous decreases in moisture content, and bending strength reached around 400 MPa. The mechanical properties of veneer laminated product did not differ significantly from those of sawn wood product. Among isotropic products, the highest bending strength at 20°C and 65% RH of plywood, particleboard and powderboard was 242 MPa, 166 MPa and 175 MPa, respectively. The difference of bending strength between plywood and other isotropic products could be explained by the difference in element orientation, cross lamination and random distribution. Furthermore, the results for the particleboard and powderboard showed that when the resin impregnated elements were hot pressed under high pressure, a decrease in element size did not result in a decrease in bending strength.

Mixtures of paper mill sludge, wood chips, bark, and peat in substrates for pot-in-pot shade tree production

There is little scientific information on substrates for pot-in-pot shade tree production. The objective of this research was to examine various organic-waste-derived substrates for growing shade trees in pot-in-pot systems. Seedling whips of green ash (Fraxinus pennsylvanica Marsh.), Japanese birch [Betula platyphylla var. japonica (Miq.) Hara], and silver maple (Acer saccharinum L.) were grown for two seasons in 76-L containers. The containers were trickle irrigated and fertilized with controlled-release fertilizers. Treatments included a control nursery mix (50% by volume of pine bark:15% compost:35% topsoil) and nine other mixes classified into three groups: Group I (25, 50 or 75% bark mixed with 50, 25, or 0% wood chips, and 25% paper mill sludge); Group II (25, 50 or 75% bark; 50, 25 or 0% wood chips; and 25% peat); and Group III (25, 50 or 75% peat; 50, 25 or 0% wood chips; and 25% paper mill sludge). In both years, trunk diameters of the three species were greatest with Group III substrates, intermediate with Group II, and least with Group I. Trunk growth was positively correlated with water retention porosity, which ranged from 42 to 57%, 38 to 42%, and 20 to 27% for Groups III, II, and I, respectively. Trunk diameters of Group II and III trees were equal to, or slightly exceeded (10–12%), those of the nursery mix. The nursery mix had a water retention porosity of 49% and generally the highest content of soluble salts. The high-peat (50 and 75%) substrates marginally but consistently produced trees with the largest trunk diameters, although with birch (not the other species) shorter trees resulted as the peat content increased. Key words: In-ground containers, nursery, ornamentals, waste utilization, container culture

Comparison of the photosynthetic capacity of Siberian and Japanese birch seedlings grown in elevated CO(2) and temperature.

The effects of increased CO(2) and temperature on the photosynthetic capacity of Siberian white birch and Japanese white birch (Betula platyphylla Sukatch. and B. platyphylla Sukatch. var. japonica Hara) were measured. Birch seedlings were raised with a CO(2) partial pressure of 36 +/- 0.3 Pa (i.e., ambient) or 70 +/- 0.6 Pa at day/night temperatures of either 30/16 degrees C or 26/12 degrees C. Siberian birch leaves were smaller and thicker than Japanese birch leaves. Water use efficiency and nitrogen use efficiency of Siberian birch grown in the CO(2)-enriched air were higher than those of Japanese birch. Both species showed a physiological adjustment to the growth CO(2) partial pressure. Carboxylation efficiency and quantum yield of both species grown in CO(2)-enriched air were lower than those of seedlings grown in ambient CO(2). The adaptation of Siberian and Japanese birch to elevated CO(2) and temperature are discussed in relation to predicted climate change.

Growth and Survival of `Whitespire' Japanese Birch Grafted on Rootstocks of Five Species of Birch

A 3-year study was conducted to evaluate growth and survival of trees grafted onto five species of birch rootstocks. `Whitespire' Japanese birch (Betula platyphylla var. japonica Hara.) was grafted onto paper birch (B. papyrifera Marsh), European birch (B. pendula Roth), river birch (B. nigra L.), Szechuan birch [B. szechuanica (C. Schneid.) Janson], and `Whitespire' Japanese birch rootstocks and grown under field conditions. Trees grafted onto river, European, paper, and `Whitespire' birch rootstocks had similar (100% to 60%) survival rates. Trees on Szechuan rootstock had a survival rate of 30%, which was lower than that of all other rootstocks, except `Whitespire'. `Whitespire' scions grafted onto European birch rootstocks had thicker trunks, were higher, and had wider canopies than trees grafted onto `Whitespire' rootstocks. Trees on river birch rootstocks also had thicker trunks but similar tree heights and canopy widths as trees grafted onto `Whitespire'. `Whitespire' Japanese birch rootstocks produced more rootstock suckers than any of the other rootstocks, while trees on river birch rootstocks had the most frost cracks. No signs of graft incompatibility were observed for any of the graft combinations. These results demonstrate that growth of `Whitespire' birch can be enhanced by grafting this cultivar on rootstocks of other species, including European and river birch.

Comparative Flood Tolerance of Birch Rootstock

The potential for enhancing flood tolerance of birches by using better adapted rootstock was evaluated. Survival, growth, and physiological responses were compared among flooded and nonflooded container-grown Japanese birch (Betula platyphylla var. japonica Hara. `Whitespire') trees grafted onto each of four rootstock: paper birch (B. papyrifera Marsh), European birch (B.pendula Roth.), river birch (B. nigra L.), and `Whitespire' Japanese birch. Separate studies were conducted in Fall 1991 and Spring 1992. Results showed no consistent differences in net photosynthesis (Pn) or survival among nonflooded plants regardless of rootstock or season, nor, were any symptoms of graft incompatibility evident. Flooding the root system for as long as 44 days revealed considerable differences among the four rootstock, with similar trends for fall and spring. Plants on river birch rootstock typically had one of the highest P rates and stomatal conductance (g,) and, in certain cases, greater mean shoot growth rates and survival of plants subjected to prolonged flooding. Although plants with European birch rootstock had survival rates similar to those of plants with river birch rootstock, plants on European birch rootstock had lower Pn under prolonged flooding, fewer late-formed roots, lower root-tip density after flooding, more abscissed leaves, and greater inhibition of shoot growth of plants flooded the previous fall. Paper and Japanese birch rootstock were most sensitive to flooding and had the lowest survival rate after flooding. However, plants on paper birch rootstock were the only plants whose Pn did not increase significantly when flooding ended; they had the most abscissed leaves during spring flooding and the greatest inhibition of shoot growth in the spring after flooding the previous fall. The four rootstock ranked from most to least flood tolerant were river > European > Japanese > paper.

Analysis of antigenic peptides obtained from Japanese birch pollen

Allergic rhinitis caused by birch pollen is common in parts of Northern Europe, North America and the northern Japanese island of Hokkaido. The major antigenic fragment of European birch (Betula verrucosa) pollen allergen with a M. W. of 17k dalton was isolated and termed Bet vI. The amino acid sequence of Bet vI has already been identified. We have attempted to identify an antigenic peptide of Japanese birch (Betula platyphylla var. Japonica) pollen allergen. Seventeen Kd fragments separated from pollen allergen by SDS-PAGE were shown to bind with IgE in the pooled sera of pollinosis patients. The fragment was digested with trypsin and fractionated by reverse phase HPLC. Five fractions were identified to have in vitro activities, such as the lymphocyte proliferative response, in pollinosis patients. Amino acid sequences of peptides in the fractions were determined. The sequence of a 12-mer peptide was shown to correspond to that of No 22-33 of Bet vI, except for the amino acid at the 31st position, phenylalanine, which was instead isoleucine. Synthetic peptides based on this sequencing were shown to cause proliferation of lymphocytes, derived from pollinosis patients, which was blocked by monoclonal antibodies to HLA-DR molecules.

COMPARATIVE FLOOD TOLERANCE OF BIRCH ROOTSTOCKS

Survival, growth, and physiological responses were compared among flooded and non-flooded container-grown trees of `Whitespire' Japanese birch (Betula platyphylla var. japonica `Whitespire') grafted onto each of four rootstocks: paper birch (B. papyrifera), European birch (B. pendula), river birch (B. nigra) and Japanese birch. Separate studies were conducted in the fall of 1991 and spring of 1992. Under flooded conditions, of up to 44 days, plants on river birch rootstocks typically had one of the greatest rates of photosynthesis Pn, stomatal conductance and, in certain cases, greater mean shoot growth rates and survival. Plants with European birch rootstock had similar survival rates to plants with river birch rootstocks, but they did not maintain as high Pn under prolonged flooding, they had less root and shoot growth, and a greater number of abscised leaves under certain conditions. Paper and Japanese birch were the two taxa found to be most sensitive to flooding and shared the ranking of lowest survival rate following flooding. These results demonstrate that flood tolerance of 'Whitespire' birch can be considerably enhance when grafted onto river birch rootstock.

Comparative drought resistance among six species of birch (Betula): influence of mild water stress on water relations and leaf gas exchange

Responses of plant water relations and leaf gas exchange to mild water stress were monitored and compared among six species of birch; monarch birch (Bet& manimowicziana Reg.), river birch (B. nigra L.), paper birch (I?. pupyrifera Marsh.), European white birch (B, pendula Roth.), ‘Whitespire’ Japanese birch (B. platyphylla var. japonica Hara. ‘Whitespire’), and gray birch (B. populifolia Marsh.). Before imposition of water stress, ‘Whitespire’ Japanese birch and river birch maintained the highest stomatal conductances and net rates of photosynthesis of the species examined. After irrigation was withheld, stomatal conductance and rate of net photosynthesis gradually declined for most species. After 28 days without irrigation, ‘Whitespire’ Japanese birch maintained significantly higher stomatal conductance and rate of net photosynthesis than did the other species despite having one of the lowest midday water potentials. There was no evidence of osmotic adjustment by any of the species in response to the imposed drought. However, there was substantial variation in the water potential at the turgor loss point among the species, from a high of -1.34 MPa for river birch to a low of -1.78 MPa for ‘Whitespire’ Japanese birch. Stomata1 conductance and net photosynthesis under mild water stress (average predawn leaf water potential of -0.6 1 MPa) were negatively correlated with leaf osmotic potential at full turgor and leaf water potential at the turgor loss point. Thus, the greater net photosynthesis of ‘Whitespire’ Japanese birch under water stress compared with the other species appears to have resulted from a superior capacity to maintain turgor at low leaf water potentials, which in turn provided for greater stomatal conductance and CO2 uptake. These results indicate that ‘Whitespire’ Japanese birch is better adapted to dry sites than the other species.

COMPARATIVE DROUGHT RESISTANCE AMONG SIX BIRCH (BETULA) SPECIES

In order to evaluate and compare adaptability to dry sites, plant water relations and leaf gas exchange were compared in response to water stress among six birch species: monarch birch (Betula maximowicziana), river birch (B. nigra), paper birch (B. papyrifera), European birch (B. pendula), `Whitespire' Japanese birch (B. platyphylla var. japonica `Whitespire'), and gray birch (B. pendula). After 28 days without irrigation, Japanese birch maintained significantly higher stomatal conductance (gs) and net photosynthesis (Pn) than did any of the other species, despite having one of the lowest mid-day water potentials. Evaluation of tissue water relations, using pressure-volume methodology, showed no evidence of osmotic adjustment for any of these species in response to water stress. However, there was substantial variation among species in the water potential at the turgor loss point; varying from a high of -1.34 MPa for river birch to a low of -1.78 MPa for Japanese birch. Rates of Pn and gs under mild stress (mean predawn leaf water potential of -0.61 MPa) were negatively correlated with leaf osmotic potential at full turgor and the leaf water potential at the turgor loss point.

Study on Neutral Sulphite CGP

Using Japanese birch, alder and oak, respectively, neutral sulphite CGP pulping was conducted to evaluate the effects of wood species, pulp yields, cooking conditions, refining and bleachina on the properties of CGP. The major results were as follows :(1) Wood species had great influence on the properties of CGP. Under the same conditions, the pulp made from birch was stronger and brighter than the pulp from alder, and the pulp from oak which was dense and dark was poorest in strength and unbleached brightness. The opacity of bleached oak CGP treated by hypochlorite was lower than that of unbleached alder or birch CGP, when their brightmess was the same.(2) At the same freeness, the strengths (e.g. breaking length) of pulps were closely related with yields and other properties of pulps. Each correlation was found to be approximately linear regardless of cooking variables. With increasing breaking length, yield, unbleached brightness and opacity decreased and sheet dencity, oil penetration and wet web strength increased. In case of oak CGP, bleach requirement increased and the opacity of bleached pulp decreased at the same brightness.(3) Lowering the freeness of pulps, the strength developed and the opacity increased in case of alder CGP having yields above 83%, and decreased in case of the lower yields pulp. At the same breaking length, the pulps of higher yield and lower freeness were superior in brightness and opacity to those of lower yield and higher freeness.(4) Bleaching developed the strength and increased the sheet density.(5) The effects of several cooking variables on the cooking rate were discussed.