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Koji?YoshidaEmail author Ryota?Shibasaki Chika?Takami Chisato?Takenaka Kazukiyo?Yamamoto Takafumi?Tezuka 《Journal of Forest Research》2004,9(3):195-203
In order to clarify the chronic influence of acid fog on the gas exchange rates of momi fir (Abies firma Sieb. et Zucc.) trees, we exposed them to simulated acid fog (pH 3) for 3 years. The composition of the acid fog was similar to that observed in a region where momi fir trees have been declining, and it contained organic acids. We then treated the firs with various additional stresses, such as drought, low temperature, fine root cutting, ozone exposure, soil acidification, nitrogen load, and rhizosphere aluminum stress. Under chronic exposure to acid fog, the momi fir seedlings exhibited a pattern of stomatal behavior whereby they excessively opened in summer and closed in winter. Furthermore, the stomata of these seedlings tended to open during drought stress, and their needles were visibly injured after ozone exposure. The net photosynthesis rates of the seedlings exposed to acid fog were regulated by their stomatal aperture, rather than directly by acid fog. These results suggest that acid fog exposure disturbs the control of stomatal function in the momi fir seedlings. In addition, we found that chronic acid fog exposure suppressed the decrease in net photosynthesis rate, due to its nitrogen load. 相似文献
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Yuko Ota Megumi K. Kimura Tsutomu Hattori Yurika Miyuki Ryota Endo 《Journal of Forest Research》2016,21(2):105-109
Trunk rot, caused by Fomitiporia torreyae, is one of the most economically important sap rot diseases on Cryptomeria japonica, especially on a cutting cultivar ‘Sanbu-sugi’. This disease had been reported only from Chiba and Ibaraki prefectures in Japan; however, a similar trunk rot on Japanese cedars was found recently in Kyoto prefecture. We identified the causal agent of the trunk rot on Japanese cedars in Kyoto prefecture, clarified the genotype of ‘Sanbu-sugi’ (sensu stricto) using microsatellite markers, and then investigated the relatedness of these infected cedars with ‘Sanbu-sugi’. The pathogen was identified as F. torreyae by its DNA sequences and morphological characteristics of the fruiting body. The 25 ramets of ‘Sanbu-sugi’ had only one genotype based on eight microsatellite loci. Infected Japanese cedars in Kyoto were comprised of different genotypes and showed no close relatedness to ‘Sanbu-sugi’. This is the first report of trunk rot caused by F. torreyae on cultivars of Japanese cedar with no relatedness to ‘Sanbu-sugi’ outside of Chiba and Ibaraki prefectures and showed the potential for expansion of this disease to Japanese cedar plantations in other areas. 相似文献
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Ryota MATSUYAMA Naotoshi KUNINAGA Tomoya MORIMOTO Tetsuya SHIBANO Akiko SUDO Kazunari SUDO Makoto ASANO Masatsugu SUZUKI Tetsuo ASAI 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2015,77(9):1179-1181
Plesiomonas shigelloides is a causal agent of gastroenteritis, sepsis
and meningitis in humans. We examined the prevalence of P. shigelloides
among great cormorants (Phalacrocorax carbo hanedae) in Japan and the
antimicrobial susceptibility of isolates. P. shigelloides was isolated
from 33 (47.8%) of 69 fecal samples from great cormorants in 2014. All 33 isolates were
subjected to antimicrobial susceptibility testing using broth microdilution methods, which
showed resistance to ampicillin (31 isolates, 93.9%), tetracycline (two isolates, 6.1%)
and trimethoprim (one isolate, 3.0%). The high prevalence of P.
shigelloides in the great cormorants implicates the possible microbiological
risk to public health. 相似文献
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We evaluated the spatial structures of nitrous oxide (N2O), carbon dioxide (CO2), and methane (CH4) fluxes in an Acacia mangium plantation stand in Sumatra, Indonesia, in drier (August) and wetter (March) seasons. A 60 × 100-m plot was established in an A. mangium plantation that included different topographical elements of the upper plateau, lower plateau, upper slope and foot slope. The plot was divided into 10 × 10-m grids and gas fluxes and soil properties were measured at 77 grid points at 10-m intervals within the plot. Spatial structures of the gas fluxes and soil properties were identified using geostatistical analyses. Averaged N2O and CO2 fluxes in the wetter season (1.85 mg N m−2 d−1 and 4.29 g C m−2 d−1, respectively) were significantly higher than those in the drier season (0.55 mg N m−2 d−1 and 2.73 g C m−2 d−1, respectively) and averaged CH4 uptake rates in the drier season (−0.62 mg C m−2 d−1) were higher than those in the wetter season (−0.24 mg C m−2 d−1). These values of N2O fluxes in A. mangium soils were higher than those reported for natural forest soils in Sumatra, while CO2 and CH4 fluxes were in the range of fluxes reported for natural forest soils. Seasonal differences in these gas fluxes appears to be controlled by soil water content and substrate availability due to differing precipitation and mineralization of litter between seasons. N2O fluxes had strong spatial dependence with a range of about 18 m in both the drier and wetter seasons. Topography was associated with the N2O fluxes in the wetter season with higher and lower fluxes on the foot slope and on the upper plateau, respectively, via controlling the anaerobic-aerobic conditions in the soils. In the drier season, however, we could not find obvious topographic influences on the spatial patterns of N2O fluxes and they may have depended on litter amount distribution. CO2 fluxes had no spatial dependence in both seasons, but the topographic influence was significant in the drier season with lowest fluxes on the foot slope, while there was no significant difference between topographic positions in the wetter season. The distributions of litter amount and soil organic matter were possibly associated with CO2 fluxes through their effects on microbial activities and fine root distribution in this A. mangium plantation. 相似文献
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Ryota Komiya Shinichiro Ogawa Tatsuya Aonuma Masahiro Satoh 《Zeitschrift für Tierzüchtung und Züchtungsbiologie》2022,139(1):113-124
Genome-wide single nucleotide polymorphism (SNP) markers in Japanese Black cattle enable genomic prediction and verifying parent–offspring relationships. We assessed the performance of opposing homozygotes (OH) for paternity testing in Japanese Black cattle, using SNP genotype information of 50 sires and 3,420 fattened animals, 1,945 of which were fathered by the 50 genotyped sires. The number of OH was counted for each sire–progeny pair in 28,764 SNPs with minor allele frequencies of ≥0.05 in this population. Across all pairs of animals, the number of OH tended to increase as the pedigree-based coefficient of relationship decreased. With a threshold of 288 (1% of SNPs) for paternity testing, most sire–progeny pairs were detected as true relationships. The frequency of Mendelian inconsistencies was 2.4%, reflecting the high accuracy of pedigree information in Japanese Black cattle population. The results indicate the utility of OH for paternity testing in Japanese Black cattle. 相似文献
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Transcription of thymic stromal lymphopoietin via Toll‐like receptor 2 in canine keratinocytes: a possible association of Staphylococcus spp. in the deterioration of allergic inflammation in canine atopic dermatitis
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Mayu Sakamoto Ryota Asahina Hiroaki Kamishina Sadatoshi Maeda 《Veterinary dermatology》2016,27(3):184-e46
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Keitaro Tawaraya Ryota Horie Tadao Wagatsuma Kazuki Saito Akira Oikawa 《Soil Science and Plant Nutrition》2018,64(3):312-322
ABSTRACTRoot exudate is derived from plant metabolites and its composition is affected by plant nutrient status. A deficiency of mineral nutrients, such as nitrogen (N) and phosphorus (P), strongly affects the type and amount of plant metabolites. We applied a metabolite profiling technique to investigate root exudates of rice plants under N and P deficiency. Oryza sativa was grown in culture solution containing two N levels (0 and 60 mg N L?1) or two P levels (0 and 8 mg P L?1). Shoot extracts, root extracts, and root exudates were obtained from the rice plants 5 and 15 days after transplanting and their metabolites were determined by capillary electrophoresis/time-of-flight mass spectrometry. Shoot N concentration and dry weight of rice plants grown at ?N level were lower than those of plants grown at +N level. Shoot P concentration and dry weight of rice plants grown at ?P level were lower than those of plants grown at +P level. One hundred and thirty-two, 127, and 98 metabolites were identified in shoot extracts, root extracts, and root exudates, respectively, at the two N levels. One hundred and thirty-two, 128, and 99 metabolites were identified in shoot extracts, root extracts, and root exudates, respectively, at the two P levels. Seventy-seven percent of the metabolites were exuded to the rhizosphere. The concentrations of betaine, gamma-aminobutyric acid, and glutarate in root exudates were higher at both ?N and ?P levels than at their respective high levels. The concentration of spermidine in root exudates was lower at both ?N and ?P levels than at their respective high levels. The concentrations of the other metabolites in root exudates were affected differently by plant N or P status. These results suggest that rice roots actively release many metabolites in response to N and P deficiency. 相似文献
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