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Kohara K.,Gifu Academy of Forest Science and Culture | Nomura T.,TOKAI RUBBER INDUSTRIES LTD. | Koumoto K.,NPO WOOD AC
Advanced Materials Research | Year: 2013

Our research team developed a brace type and an angle brace type of the visco-elastic damper on seismic-response controlled structure for timber structure. We performed various dependence evaluations by the materials examination of the styrene olefin-based visco-elastic body which we developed newly. We made a structural model using the performance that loading tests in timber frame. We inspected the validity of the structural model. In addition, we built a technical support system for damper setting by the time history response analysis so that a general design architect was easy to use the damper. We could express dynamics properties of visco-elastic body properties by Voigt model, and the structural model almost accorded with an examination property value. We made a structural model of the whole frame system by Kb of installation rigidity obtained from loading tests in timber frame. Because a design level almost accorded with experimental value, the validity of the frame design on seismic-response controlled structure in consideration of the dependence (distortion, frequency, temperature) of the visco-elastic body was confirmed. This visco-elastic damper on seismic-response controlled structure acquired minister authorization of Ministry of Land, Infrastructure and Transport. In addition, this damper acquired the certification of the Japan Building Disaster Prevention Association. © (2013) Trans Tech Publicutions, Switzerland.

Tsuda K.,Gifu Academy of Forest Science and Culture
Nihon Ringakkai Shi/Journal of the Japanese Forestry Society | Year: 2012

The genus Iotonchium is one of the nematode groups utilizing fruiting bodies of basidiomycetous fungi. They have two ecological phases in their life cycles, i.e., mycetophagous phase living in mushrooms and insect-parasitic phase parasitizing mycetophilid gnats. In this genus, 11 species have been reported in the world, however, only 5 species, including 4 Japanese species, have been clarified the details of their life cycles. Iotonchium ungulatum, a pathogen of gill-knot disease of the oyster mushroom, is known to generate nematode-galls (knots) on the gills of fruiting bodies of Pleurotus fungi. Other Iotonchium species do not generate knots and inhabit the tissue of fruiting bodies of host fungi. Iotonchium nematodes are supposed to have close relationships with mycetophilid gnats. In the amber, their relative species has been discovered with the mycetophilid fossil. This review highlights the tripartite relationship of these organisms and discusses their evolutionary relationship and the future directions of research on this topic.

Kohara K.,Gifu Academy of Forest Science and Culture | Tsuji M.,Gifu Academy of Forest Science and Culture
11th World Conference on Timber Engineering 2010, WCTE 2010 | Year: 2010

It aims at grasping educational effect by the execution of the inhabitant participation workshop about the design of the timber building which the regional timbers was used for. The cases to carry out the workshop of the inhabitant participation increase about the construction of the public facilities in Japan. We must verify effect to go through the design of the timber building by this technique. It is specially grasped about the educational effect in this research. Our research group affected the design of the timber building of two facilities by the inhabitant participation workshop. The people who joined the workshop are supporting management actively and there are many visitors than the planned visitors. It became a building with the story which the regional timbers were used for, and became the building where an attachment was popular with both facilities by the design through the workshop by the local residents.

Tamaki I.,Gifu Academy of Forest Science and Culture | Setsuko S.,Japan Forestry and Forest Products Research Institute | Tomaru N.,Nagoya University
Conservation Genetics | Year: 2016

Understanding the factors shaping rare species’ current genetic diversity and structure, particularly the impact of recent anthropogenic pressures, is important in order to develop appropriate conservation strategies based on robust predictions. Thus, we have genotyped all 585 surviving individuals of Magnolia stellata from six remnant populations and seven isolated tree sites in northern Mie Prefecture, Japan, using nuclear and chloroplast microsatellites. Three genetic clusters were detected by STRUCTURE analysis, with an oldest divergence time between pairs within 25 generations according to coalescent analysis. We attribute this recent divergence to recent anthropogenic environmental changes. Evidence of only one significant recent migration event between pairs of the six populations was detected, indicating that most of the remnant populations are isolated now. Their future genetic status was predicted using Monte Carlo simulations, under four scenarios. It declined more than twice as rapidly in a scenario assuming variations in fecundity among both female and male parents than in a scenario assuming no fecundity variations, but strongly improved in a scenario including promotion of migrations between adjacent pairs of populations. These predictions indicate that sexual reproduction of the species should be promoted by providing more suitable habitats and migration between populations should be enhanced by restoring remnant isolated tree sites and extinct populations. In addition, all the remnant populations should be conserved because they host current genetic variation that may be important for coping with future climate change, and they could provide important stepping-stones for gene flow. © 2016 Springer Science+Business Media Dordrecht

Tamaki I.,Gifu Academy of Forest Science and Culture | Okada M.,Gifu Academy of Forest Science and Culture
Tree Genetics and Genomes | Year: 2014

In forests worldwide, Quercus is a major genus; however, the boundaries between the constituent species are relatively weak, and hybridization is reported frequently. In this study, we examined Quercus acuta and Quercus sessilifolia (subgenus Cyclobalanopsis), which have a putative hybrid-Q. x takaoyamensis. We investigated leaf morphological traits and microsatellites of Q. acuta and Q. sessilifolia in the area where the two species are both found. Although the leaf traits overlapped, the two species could be distinguished morphologically as demonstrated by principal component analysis based on a range of these traits. They were also genetically differentiated, with F ST = 0.104. However, they shared most of the alleles at all eight loci examined, and considerable genetic admixing was detected. Admixture analysis demonstrated that Q. acuta and Q. sessilifolia, respectively, contained 11 and 24 % of individuals with a probability of less than 0.9 of being correctly assigned to their species. Model-based testing showed that this admixing was created by not only shared ancestral polymorphism but also by hybridization. Effective population size and migration rate were estimated using the coalescent approach. We estimated 8.843 and 71.98 effective numbers of migrants per generation to Q. acuta and Q. sessilifolia, respectively. Theoretically, one to ten migrants per generation are required to prevent complete genetic differentiation. Based on the results of this study, it appears that genetic admixing, with sharing of most alleles, is probably common in the two species and is maintained by interspecific introgressive hybridization. © 2014 Springer-Verlag Berlin Heidelberg.

Tamaki I.,Gifu Academy of Forest Science and Culture | Kuze T.,Gifu Academy of Forest Science and Culture | Hirota K.,Gifu Academy of Forest Science and Culture | Mizuno M.,Gifu Pharmaceutical University
Genetic Resources and Crop Evolution | Year: 2016

Tea, Camellia sinensis, is economically, medicinally and culturally a very important crop. Most of the tea gardens in Japan contain clonally propagated cultivars; however, landraces that were propagated by seed contain valuable genetic variations, providing important resources for future tea breeding. Genetic diversity and differentiation, as well as the population demography of ten landrace populations in Kasuga, Gifu, Japan were investigated using microsatellite markers. All ten populations showed similar levels of genetic variation and there was no significant differentiation between them. These ten populations can be considered to represent a single large population. Gene flow between them may be natural or the result of artificial but random seed exchange by local farmers. The level of genetic diversity in the Kasuga population was compared with that in Kyoto and in China. Kasuga and Kyoto showed similar levels of genetic diversity and this suggests that the value of genetic resources in these two regions is about equal. The level of genetic diversity in Kasuga was much lower than that in China. A coalescent approach revealed that the Kasuga population suffered from severe population reduction (0.1 %) 965 years ago and then exponentially expanded to its current level. This timing and the strength of the bottleneck corresponds to the time when tea plants were brought to Japan from China by Buddhist priests in the ninth–twelfth century. Lower genetic diversities in Japanese populations are thus considered to be the result of the small number of founders brought from China. © 2015, Springer Science+Business Media Dordrecht.

Tani S.,Nagoya University | Tamaki I.,Gifu Academy of Forest Science and Culture | Setsuko S.,Japan Forestry and Forest Products Research Institute | Tomaru N.,Nagoya University
Nihon Ringakkai Shi/Journal of the Japanese Forestry Society | Year: 2014

We conducted reciprocal interspecific crosses between Magnolia stellata and M. salicifolia and investigated whether there are differences in the development of fruits and seeds and the germination rate of seeds between reciprocal interspecific crosses. After 60-90 days from the hand pollination, the proportion of aborted fruits was higher for the interspecific cross of M. stellata as maternal parents than for that of M. salicifolia as maternal parents. Moreover, the fruit set, seed set and female reproductive success in the interspecific cross of M. stellata as maternal parents were all lower than those of M. salicifolia as maternal parents. The germination rate of seeds produced from the interspecific crosses in which maternal parents were M. stellata was lower than that in which maternal parents were M. salicifolia, but its difference was not statistically significant. Therefore, the occurrence of unidirectional interspecific hybridization in which M. salicifolia is a maternal parent and M. stellate is a paternal parent under nature conditions may be caused mainly by a failure in the fruit maturation and seed development in the interspecific cross of M. stellate as maternal parents.

Muranishi S.,Nagoya University | Tamaki I.,Gifu Academy of Forest Science and Culture | Setsuko S.,Japan Forestry and Forest Products Research Institute | Tomaru N.,Nagoya University
Tree Genetics and Genomes | Year: 2013

In order to understand the ongoing evolutionary relationships between species, it is important to elucidate patterns of natural hybridization. In the zone where two species are sympatrically distributed, we examined 274 individuals of Magnolia stellata, Magnolia salicifolia, and their putative hybrids by means of 16 nuclear and three chloroplast microsatellite markers. Hybrid classes of individuals were estimated by admixture analyses. Morphological traits were also investigated for 64 of the 274 individuals. Admixture analyses revealed that 66 of the 274 individuals were classified as hybrids, comprising 17 F1 and 19 F2 individuals, 27 backcrosses to M. salicifolia, and 3 individuals of unknown origin. Morphological data from the 64 individuals agreed well with their genetic admixture rates. Spatial locations of F1 and F2 hybrids at the study site were intermediate between the two purebred species, indicating that the site preferences of hybrids are intermediate. The occurrences of F2 and backcross hybrids indicate that F1 hybrids are fertile. The chloroplast DNA haplotypes of all F1 hybrids corresponded to those detected in M. salicifolia, so that maternal parents of the F1 hybrids were all M. salicifolia. Furthermore, no hybrid individuals derived from a backcross to M. stellata were detected. These results suggest that the direction of hybridization and the subsequent introgression have been quite asymmetric and that the introgression occurred from M. stellata into M. salicifolia. © 2013 Springer-Verlag Berlin Heidelberg.

PubMed | Japan Forestry and Forest Products Research Institute and Gifu Academy of Forest Science and Culture
Type: Journal Article | Journal: Applications in plant sciences | Year: 2016

Microsatellite markers were developed for a dioecious shrub, Sixteen polymorphic microsatellite markers were identified by 454 next-generation sequencing. The number of alleles and expected heterozygosity for each locus among four populations ranged from two to 10 and from 0.140 to 0.875, respectively. Five of the 16 loci showed a low null allele frequency. Because These microsatellite markers developed for

PubMed | University of Zürich, Kyoto University, Gifu Academy of Forest Science and Culture and Kanazawa University
Type: Journal Article | Journal: Journal of plant research | Year: 2016

Whole genome sequences, which can be provided even for non-model organisms owing to high-throughput sequencers, are valuable in enhancing the understanding of adaptive evolution. Metrosideros polymorpha, a tree species endemic to the Hawaiian Islands, occupies a wide range of ecological habitats and shows remarkable polymorphism in phenotypes among/within populations. The biological functions of genetic variations observed within this species could provide significant insights into the adaptive radiation found in a single species. Here de novo assembled genome sequences of M. polymorpha are presented to reveal basic genomic parameters about this species and to develop our knowledge of ecological divergences. The assembly yielded 304-Mbp genome sequences, half of which were covered by 19 scaffolds with>5 Mbp, and contained 30K protein-coding genes. Demographic history inferred from the genome-wide heterozygosity indicated that this species experienced a dramatic rise and fall in the effective population size, possibly owing to past geographic or climatic changes in the Hawaiian Islands. This M. polymorpha genome assembly represents a high-quality genome resource useful for future functional analyses of both intra- and interspecies genetic variations or comparative genomics.

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