Brown root rot of Russell prairie gentian caused by Subplenodomus drobnjacensis     

Toru Kondo  Mamoru Satou  Toshiyuki Morikawa  Yoshiaki Chikuo 《Journal of General Plant Pathology》2014,80(1):99-102

Brown root rot of Russell prairie gentian was observed in the Aomori Prefecture, Japan in April 2011. The fungal isolate from the diseased root was identified as Subplenodomus drobnjacensis on the basis of its morphological characteristics and nucleotide sequences. The isolate induced similar root rot symptoms when inoculated in healthy Russell prairie gentian plants. We proposed the name “brown root rot” for this disease.  相似文献   

Greater disruption due to failure of inhibitory control on an ambiguous distractor     

Tsushima Y  Sasaki Y  Watanabe T 《Science (New York, N.Y.)》2006,314(5806):1786-1788

Considerable evidence indicates that a stimulus that is subthreshold, and thus consciously invisible, influences brain activity and behavioral performance. However, it is not clear how subthreshold stimuli are processed in the brain. We found that a task-irrelevant subthreshold coherent motion led to a stronger disturbance in task performance than did suprathreshold motion. With the subthreshold motion, activity in the visual cortex measured by functional magnetic resonance imaging was higher, but activity in the lateral prefrontal cortex was lower, than with suprathreshold motion. These results suggest that subthreshold irrelevant signals are not subject to effective inhibitory control.  相似文献   

Effects of brassinolide on the growing of rice plants     

Yoshiaki Nakagawa  Bunta Nishikawa  Hisashi Miyagawa 《Journal of Pesticide Science》2021,46(3):274

Brassinosteroids are plant steroid hormones that are essential for plant growth. When germinated rice seeds were treated with brassinolide (BL), stems were elongated and root spiral formation was observed at 5 nM of BL. Such root spiral formation was not induced by other plant hormones such as auxin and gibberellin. Since weak non-steroidal brassinolide-like compound (NSBR1) also induced spiral formation, this root spiral induction can be used as the index in the search for BL-like compounds.  相似文献   

Field survey of ranunculus mild mosaic virus,tomato spotted wilt virus and cucumber mosaic virus infections in <Emphasis Type="Italic">Ranunculus asiaticus</Emphasis> L. in Japan by newly developed multiplex RT-PCR     

Saki Hayahi  Yosuke Matsushita  Yoshiaki Kanno  Yoshiyuki Kushima  Satoshi Teramoto  Minoru Takeshita 《European journal of plant pathology / European Foundation for Plant Pathology》2018,150(1):205-212

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Assessment of species specificity of moulting accelerating compounds in Lepidoptera: comparison of activity between Bombyx mori and Spodoptera littoralis by in vitro reporter and in vivo toxicity assays     

Thomas Soin  Ellen De Geyter  Hadi Mosallanejad  Masatoshi Iga  David Martín  Shunsuke Ozaki  Shigeki Kitsuda  Toshiyuki Harada  Hisashi Miyagawa  Dimitra Stefanou  Georgia Kotzia  Rodica Efrose  Vassiliki Labropoulou  Danny Geelen  Kostas Iatrou  Yoshiaki Nakagawa  Colin R Janssen  Guy Smagghe  Luc Swevers 《Pest management science》2010,66(5):526-535

BACKGROUND: Dibenzoylhydrazine analogues have been developed successfully as a new group of insect growth regulators, called ecdysone agonists or moulting accelerating compounds. A notable feature is their high activity against lepidopteran insects, raising the question as to whether species‐specific analogues can be isolated. In this study, the specificity of ecdysone agonists was addressed through a comparative analysis in two important lepidopterans, the silkworm Bombyx mori L. and the cotton leafworm Spodoptera littoralis (Boisd.). RESULTS: When collections of non‐steroidal ecdysone agonists containing different mother structures (dibenzoylhydrazine, acylaminoketone, tetrahydroquinoline) were tested, in vitro reporter assays showed minor differences using cell lines derived from both species. However, when compounds with high ecdysone agonist activity were examined in toxicity assays, larvicidal activity differed considerably. Of note was the identification of three dibenzoylhydrazine analogues with > 100‐fold higher activity against Bombyx than against Spodoptera larvae. CONCLUSION: The present study demonstrated that species‐specific ecdysone‐agonist‐based insecticides can be developed, but their species specificity is not based on differences in the activation of the ecdysone receptor but rather on unidentified in vivo parameters such as permeability of the cuticle, uptake/excretion by the gut or metabolic detoxification. Copyright © 2010 Society of Chemical Industry  相似文献   

N applications that increase plant N during panicle development are highly effective in increasing spikelet number in rice   总被引：2，自引：0，他引：2  

Yoshiaki Kamiji  Hiroe YoshidaJairo A. Palta  Tetsuo SakurataniTatsuhiko Shiraiwa 《Field Crops Research》2011,122(3):242-247

Efficient use of nitrogen fertilizer is critical in improving yield stability in rice. The objective of this study was to determine the effect of nitrogen (N) top-dressing on the number of total spikelet (fertile plus sterile) production and evaluate the effect among rice cultivars. We analyzed 136 sets of experimental data on growth and spikelet production for three lowland cultivars, grown under various regimes of N over 10 seasons at Kyoto, Ibaraki and Kanagawa, Japan. In each season, one to three of the lowland cultivars, Nipponbare (japonica), Koshihikari (japonica) and Takanari (indica), were studied. In 1986, 1995 and 1999-2001, the N regimes included basal application only, light basal and heavy top-dressing from the panicle initiation stage onward, heavy basal and heavy top-dressing from the spikelet formation stage onward, and no applications. In 2002 and 2005-2008, we set up experimental plots with varied time of N top-dressing, with or without N basal application. Takanari had the largest spikelet number averaged over all plots and was considered better efficient in spikelet production per applied N than the other cultivars. Although the trend is not clear, the effect of time of top-dressing on spikelet number was generally the greatest when N was top-dressed from 35 to 30 days before heading. The variation of observed spikelet number was analyzed with a linear regression of plant N 14 days before heading and by a model that estimates spikelet production accounting for plant N 14 days before heading and crop growth rate (CGR) during the 14-day period preceding heading. For the variation of spikelet number within each cultivar, the linear function model expressed the observed spikelet number than the two function model with R² 0.43** versus 0.13*-0.28** for the former and later models, respectively. When the results of all cultivars were combined, the two function model was much better for estimation of spikelet number than the linear function model (R² = 0.36** vs. 0.20*). This indicates that yearly and varietal variation of spikelet number was caused mainly by plant N status at the late spikelet differentiation stage. The varietal variation in spikelet production efficiency is explained by CGR during this 14-day period. We concluded that N applications that increase plant N 14 days before heading is highly effective in maximizing spikelet production among cultivars.  相似文献   

Quantitative structure–activity studies of insect growth regulators: XVI. Substituent effects of dibenzoylhydrazines on the insecticidal activity to Colorado potato beetle Leptinotarsa decemlineata     

Yoshiaki Nakagawa  Guy Smagghe  Soichi Kugimiya  Kazunari Hattori  Tamio Ueno  Luc Tirry  Toshio Fujita 《Pest management science》1999,55(9):909-918

Insecticidal activity against the Colorado potato beetle, Leptinotarsa decemlineata, was measured for a series of substituted N-tert-butyl-dibenzoylhydrazines, in which one of the benzoyl moieties closer to the tert-butyl group was fixed as being 2-chloro-substitued and the other variously substituted singly or doubly. The effects of substituents on the activity were quantitatively analysed using the classical quantitative structure–activity relationship (QSAR) procedure. The activity against the Colorado potato beetle increases with the molecular hydrophobicity. In addition, various types of steric effect are at work, depending upon the positions. Hydrogen-bonding acceptor substituents at the para position enhance the activity. There seem to be threshold (or optimum) values, albeit position-dependent, in the molecular hydrophobicity, above which the activity starts to decrease. This biphasic contribution of the molecular hydrophobicity to activity against coleopterous larvae is the most conspicuous difference in substituent effects from those found for similar compounds against lepidopterous pest insects, and may be the basis of the variations in the activity spectrum for certain compounds in this series. The introduction of bulkier substituents into the meta- and para-positions of the benzene ring, apart from the tert-butyl group, is unfavorable to activity. LD₅₀ values against Colorado potato beetle larvae of methoxyfenozide (RH-2485) and tebufenozide (RH-5992) were in the order of 10⁻⁷ mol per insect, whereas those of RH-5849, and halofenozide (RH-0345) were very low, 10⁻⁹–10⁻¹⁰ mol per insect being selective to the coleopterous larvae. © 1999 Society of Chemical Industry  相似文献   

Development of a system for measuring calcitonin in the stingray Dasyatis akajei (a cartilaginous fish): the possible involvement of stingray calcitonin in gonadal development     

Takashi Takagi  Toshio Sekiguchi  Yuichi Sasayama  Atsuhiko Hattori  Takushi X. Watanabe  Yoichiro Kitani  Yoshiaki Tabuchi  Hajime Matsubara  Ajai K. Srivastav  Tran Ngoc Hai  Thumronk Amornsakun  Nobuo Suzuki 《International Aquatic Research》2019,11(3):267-276

To elucidate the physiological role of calcitonin (CT) in stingrays (cartilaginous fish), an enzyme-linked immunosorbent assay (ELISA) system using a specific antibody against stingray CT has been developed. Synthetic stingray CT was subcutaneously injected into mice four times—once every 2 weeks—together with an adjuvant. We purified the IgG antibody fraction using the protein A affinity chromatography from collected antiserum. Evaluating the antibody titer, we found the antibody’s optimum dilution ratio to be 600 times. Competitive ELISA has been developed using the antibody diluted 600 times. Our antibody did not cross-react with teleost CTs and muscle extraction, but cross-reacted with stingray plasma and the extract of the ultimobranchial gland, the secretary organ of stingray CT. Using this ELISA, we measured the plasma CT level in stingrays and examined its correlation with several mineral concentrations. Plasma CT did not show significant correlation to calcium, magnesium, inorganic phosphorus, sodium, chlorine, or urea, although there was a correlation among the factors involved in osmoregulation, such as sodium, chlorine, and urea. On the other hand, plasma CT was significantly correlated to body weight and length. Furthermore, there was a significant correlation between plasma CT and gonad weight. Since plasma CT was correlated with the weight of liver, which is involved in the synthesis of egg yolk protein, we examined the influence of 17β-estradiol (E2) on CT secretion. After E2 injection, the plasma CT level increased significantly. This is the first study to demonstrate that E2 induced plasma CT secretion in cartilaginous fish.  相似文献   

Effect of extracts from <Emphasis Type="Italic">narezushi</Emphasis>, a fermented mackerel product,on cholesterol metabolism in Wistar rats     

Kouji Itou  Yoshiaki Akahane 《Fisheries Science》2010,76(3):537-546

Narezushi extract was separated into peptide and nonpeptide fractions by ion-exchange column chromatography. The narezushi extract and fractions were administered to rats in a diet enriched with lipid and cholesterol for 30 days. In the narezushi extract and nonpeptide fraction groups, increases in triglyceride, total cholesterol, and low-density lipoprotein-cholesterol levels in the plasma and accumulation of total lipids and triglyceride in the liver were suppressed, while both lipid and cholesterol fecal excretion were increased. In the peptide fraction group, these effects were also observed, except for the suppressing effect on liver lipid accumulation. Narezushi extract administration tended to increase fecal bile acids and promoted the activity of cholesterol 7α-hydroxylase, the rate-limiting enzyme in the synthesis of bile acid from cholesterol in the liver. However, the activity of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase, the rate-limiting enzyme in the cholesterol synthesis system in the liver, decreased due to regulation by the feedback of lipid transportation from diet to the liver. These results suggest that both the increase in cholesterol and bile acid fecal excretion and the promotion of cholesterol 7α-hydroxylase activities are related to the hypocholesterolemic effects of narezushi extract. Amino acids and organic acids, which are abundantly contained in the nonpeptide fraction, seemed to have more intensive hypocholesterolemic effects than peptides existing in the peptide fraction.  相似文献   

Transcription‐inducing activity of natural and synthetic juvenile hormone agonists through the Drosophila Methoprene‐tolerant protein     

Taiyo Yokoi  Taku Nabe  Chiharu Ishizuka  Ken'ichiro Hayashi  Sayoko Ito‐Harashima  Takashi Yagi  Yoshiaki Nakagawa  Hisashi Miyagawa 《Pest management science》2020,76(7):2316-2323

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